A body moves in a straight line. At time, it's acceleration is given by a = 12t + 1. When t =0, the velocity of the body v is 2 metres per second and its displacement from the origin s is 0.
1. Express v and s in terms of t.
2. Determine velocity and displacement of the body after 3 seconds. ​

Answers

Answer 1

Answer:

v = 6t² + t + 2, s = 2t³ + ½ t² + 2t

59 m/s, 64.5 m

Explanation:

a = 12t + 1

v = ∫ a dt

v = 6t² + t + C

At t = 0, v = 2.

2 = 6(0)² + (0) + C

2 = C

Therefore, v = 6t² + t + 2.

s = ∫ v dt

s = 2t³ + ½ t² + 2t + C

At t = 0, s = 0.

0 = 2(0)³ + ½ (0)² + 2(0) + C

0 = C

Therefore, s = 2t³ + ½ t² + 2t.

At t = 3:

v = 6(3)² + (3) + 2 = 59

s = 2(3)³ + ½ (3)² + 2(3) = 64.5


Related Questions

the velocity is always _____ to the line of a circle

Answers

Answer:

tangent

Explanation:

hope it helps

Answer:

the answer is tangent

Explanation:

tangent means a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.

hope this helps please like and heart this answer and give 5 stars and brainliest pls i beg u thx!!! : )

what is the meaning of physics​

Answers

Answer:

the branch of science concerned with the nature and properties of matter and energy

250 mL 0.1 M HCl solution is mixed with 250 mL
0.2 M NaOH. The concentration of OH- in the
mixture is

Answers

Answer:

The concentration of OH⁻ in the mixture is 0.05 M

Explanation:

The reaction of neutralization between HCl and NaOH is the following:

H⁺(aq) + OH⁻(aq) ⇄  H₂O(l)

The number of moles of HCl is:

[tex] n_{HCl} = C*V = 0.1 mol/L*0.250L = 0.025 moles [/tex]

Similarly, the number of moles of NaOH is:

[tex] n_{NaOH} = C*V = 0.2 mol/L*0.250L = 0.05 moles [/tex]

Now, from the reaction of HCl and NaOH we have the following number of moles of NaOH remaining:

[tex] n_{NaOH} = 0.05 moles - 0.025 moles = 0.025 moles [/tex]

Finally, the concentration of OH⁻ in the mixture is:

[tex]C =\frac{n_{NaOH}}{V_{T}}=\frac{0.025 moles}{0.250*2 L} = 0.05 moles/L[/tex]

Therefore, the concentration of OH⁻ in the mixture is 0.05 M.

I hope it helps you!

One solution to minimize resonance with buildings is to ______ the width to span ratio.

Answers

Answer:

Increase

Explanation:

Resonance is a phenomenon which occurs when a body A in motion set another body B into motion of it own natural frequency. So for resonance to be minimize in a body is to increase the width to span ratio. So as to reduce the overall vibration which affects directly building resonance, the stiffness or trusses and girders should be increase. The increase in this aspect helps to reinforce building structure and support.

A ball is thrown vertically upwards from the roof of a building with an initial velocity of 30 m / s. If it stops in the air 220 m above the ground, what is the height of the building?

Answers

Answer:

175 m

Explanation:

Given:

y = 220 m

v₀ = 30 m/s

v = 0 m/s

a = -10 m/s²

Find: y₀

v² = v₀² + 2a (y − y₀)

(0 m/s)² = (30 m/s)² + 2 (-10 m/s²) (220 m − y₀)

y₀ = 175 m

Energy of the fossil fuels is also derived from solar energy. Give reason.​

Answers

Answer:

Explanation:

All the energy in oil, gas, and coal originally came from the sun, captured through photosynthesis. In the same way that we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun

2.0 MW is to arrive at a large shopping mall over two 0.100Ω lines. Estimate how much power is saved if the voltage is stepped up from 120 V to 1200 V and then down again, rather than simply transmitting at 120 V. Assume the transformers are each 99% efficient.

Answers

Answer:

55 MW.

Explanation:

So, we are given the following data or parameters Below;

=> "2.0 MW is to arrive at a large shopping mall over two 0.100Ω line.

=> " the voltage is stepped up from 120 V to 1200 V and then down again, rather than simply transmitting at 120 V."

=> "Assume the transformers are each 99% efficient."

STEP ONE: determine the current in the transmission line.

Output Current, i = Power/ voltage.

Output Current,i = (2.0 MW × 10^6 W/ 1 MW)/120.

Output Current,i = 1.66 × 10^4 A.

Therefore, current in the transmission line = output voltage × output current/99% × line voltage.

= 120 × 1.66 × 10^4/ 99% × 1200 = 1.68 × 10^3 A.

STEP TWO: determine the power loss in the two lines.

Power loss = i^2 × Resistance

Power loss = (1.66 × 10^4 )^2 × 0.1 × 2 = 5.5 × 10^7 watt.

STEP THREE: determine the power generated.

Power generated = 2 × 10^6 +5.5 × 10^7.

Power generated = 5.57 × 10^7 watt.

STEP FOUR: determine the step down transformer power.

= 2 × 10^6/99% = 2.02 × 10^6.

Thus, 2.02 × 10^6 + 5.57 × 10^5 = 2.58 × 10^6 watt.

STEP FIVE: Determine the total power and the saved power.

Total power = 2.58 × 10^6/ 99%= 2.6 × 10^6.

Saved power = 5.7 × 10^7 - 2.6 × 10^6 .

Conversion to MW gives saved power = 55 MW.

=

Power is _________________the force required to push something the work done by a system the speed of an object the rate that the energy of a system is transformed the energy of a system

Answers

Answer:

[defined as]

Explanation:

it is the missing word

Power is (defined as) the force...

Four identical point charges (+6.0 nC) are placed at the corners of a rectangle which measures 6.0 m×8.0 m. If the electric potential is taken to be zero at infinity, what is the potential at the geometric center of this rectangle

Answers

Substitute the values

The electric potential at the geometric center of this rectangle is determined as 43.2 V.

Potential at the center of the rectangle

Potential at the center of the rectangle is calculated as follows;

Let the distance from each corner to the center = xLet the length = aLet the breadth = b

Distance from each corner to the center is calculated as follows;

[tex]x = \sqrt{(a/2)^2 + (b/2)^2}[/tex]

Potential due to four point charges is calculated

[tex]V = \frac{kq}{x} \\\\V =4 (\frac{kq}{x} )\\\\V = 4(\frac{kq}{\sqrt{(a/2)^2 + (b/2)^2} } )\\\\V = \frac{4 \times 9\times 10^{9}\times 6\times 10^{-9}}{\sqrt{(6/2)^2 + (8/2)^2} } \\\\V = \frac{4 \times 9\times 10^{9}\times 6\times 10^{-9}}{5} \\\\V = 43.2 \ Volts[/tex]

Learn more about electric potential here: https://brainly.com/question/14306881

#SPJ2

The north pole of a bar magnet is rapidly introduced into a solenoid at one end (say A). Which of the following statements correctly depicts the phenomenon taking place?
(a) No induced emf is developed.
(b) The end A of the solenoid behaves like a south pole.
(c) The end A of the solenoid behaves like north pole.
(d) The end A of the solenoid acquires positive potential.

Answers

Answer:

The correct option is;

(b) The end A of the solenoid behaves like a north pole

Explanation:

According to Lenz's law we have that the induced emf direction in the solenoid due to the rapid introduction of the bar magnet will be such that the electric current induced will have a resultant magnet field that will  oppose to the movement of the north pole of the bar magnet that resulted in the magnetic field

Therefore, the opposing magnetic pole to the north pole of a magnet is a north pole and the solenoid end A will act like the north pole.

Click this link to view O*NET Skills section for Electrical Engineers. Note that common skills are listed toward the top and less common skills are listed toward the bottom. According to O*NET, what are some common skills Electrical Engineers need?

Answers

Explanation:

O*NET stands for Occupational Network and it is an online platform for job seekers around the world who are searching for jobs. This platforms provides the job information along with the required qualities, education background, skill sets, etc.

The most common skill sets that are required for an electrical engineers are

1. Analytical skills

2. Monitoring and active learning

3. Decision making

4. Able to manage the personal resources

5. Time management.

6. Should have knowledge about different software.

the answers are1, 4, 5, 6orA, D, E, F

Calculate the acceleration of a mobile that at 4s is 32m from the origin, knowing that its initial speed is 10m / s.

Answers

Answer:

5.5 m/s^2

Explanation:

I believe this is the answer > using the formula a= v-v0/t

Hope this helps!

Answer:

-1 m/s²

Explanation:

Given:

Δx = 32 m

v₀ = 10 m/s

t = 4 s

Find: a

Δx = v₀ t + ½ at²

32 m = (10 m/s) (4 s) + ½ a (4 s)²

a = -1 m/s²

what is a primary source?

Answers

Answer:

A primary source is an original document such as diaries, speeches, manuscripts, letters, interviews, records, eyewitness accounts, autobiographies. Empirical scholarly works such as research articles, clinical reports, case studies, dissertation

Explanation:

Answer:

Scientific paper

Explanation:

A p e x

Train cars are coupled together by being bumped into one another. Suppose two loaded train cars are moving toward one another, the first having a mass of 270000 kg and a velocity of 0.325 m/s in the horizontal direction, and the second having a mass of 52500 kg and a velocity of -0.12 m/s in the horizontal direction. What is their final velocity?

Answers

Answer:

0.252 m/s

Explanation:

Applying the law of conservation of momentum,

Total momentum before collision = Total momentum after collision

Note: From the question, The collision between the car and the train is an inelastic collision and as such, both move with a common velocity after collision.

mu+m'u' = V(m+m')................... Equation 1

Where m = mass of the train, u' = initial velocity of the train, m' = mass of the car, u' = initial velocity of the car, V = common velocity after collision.

make V the subject of the equation

V = (mu+m'u')/(m+m')............... Equation 2

Given: m = 270000 kg, u = 0.325 m/s, m' = 52500 kg, u' = -0.12 m/s

Substitute these values into equation 2

V = [(270000×0.325)+{52500(-0.12)}]/(270000+52500)

V = 81450/322500

V = 0.252 m/s

Which of the following does each different kind of atom represent?
O A. A nucleus
O B. An element
O C. An electron
OD. A neutron​

Answers

Answer:

B

Explanation:

because atoms make up an element.

Answer:

B

Explanation:

it's b because an element makes up an atom and signifies the number of element in atom e.g (H2) the two signifies the number of atoms

Which property describes the amount of energy that flows past a given area
per unit of time?
A. Wavelength
B. Speed
c. Intensity
D. Pitch

Answers

Answer:

c. Intensity

Explanation:

Wavelength is a distance (meters).

Speed is distance per time (meters / second).

Intensity is power per area (Watts / square meter).

Pitch is frequency (cycles / second).

An object weighs 0.250 kgf in air, 0.150 kgf in water and 0.125 kgf in an oil.
Find out the density of the object and the oil.​

Answers

Answer: Upthrust = Weight - Apparent weight

= 0.250 kgf - 0. 150 kgf

= 0.100 kgf

Density = mass / volume

volume = mass / density

= 0.100 kg / (1000 kg / m³)

= 0.0001 m³

density of object  = mass / volume

= 0.250 kg / 0.0001 m³

= 2500 kg / m³

upthrust of oil = Weight - Apparent weight

= 0.250 kgf - 0.125 kgf

= 0.125 kgf

density = mass / volume

= 0.125 kg / 0.0001 m³

= 1250 kg/m³

density of the object = 2500 kg / m³

density of oil = 1250 kg / m³

which discribes what a velocity/time graph would look like with no accelaration

Answers

It would be a straight line. No acceleration means constant velocity.

A ball is projected at an angle of elevation of 60 ° with an initial velocity of 120m/s.calculate
1) The time taken to get to the maximum height
ii) the time of flight ​

Answers

Explanation:

It is given that,

The angle of projection is 60 degrees

Initial velocity of the ball is 120 m/s

We need to find the time taken to get to the maximum height and the time of flight.

Time taken to reach the maximum height is given by :

[tex]T=\dfrac{u^2\sin^2\theta}{2g}[/tex]

g is acceleration due to gravity

[tex]T=\dfrac{(120)^2\times \sin^2(60)}{2\times 10}\\\\T=540\ s[/tex]

(ii) Time of flight,

[tex]t=\dfrac{2u\sin\theta}{g}[/tex]

So,

[tex]t=\dfrac{2\times 120\times \sin(60)}{10}\\\\t=20.78\ s[/tex]

Hence, this is the required solution.

A man has a mass of 110kg. What is his weight?

Answers

His weight depends on where he is, because

Weight = (mass) x (gravity in the place where the mass is) .

For example:

-- If this man is on Mars, his weight is (110 kg) x (3.7 m/s²) =  408 Newtons

-- If he is on the Moon, his weight is (110 kg) x (1.6 m/s²) =  176 Newtons

-- If he is on Earth, his weight is (110 kg) x (9.8 m/s²) =  1,078 Newtons

-- If he is in a spacecraft coasting from one to another, his weight is zero.

A 0.675 kg mass is attached to a
spring of spring constant 72.4 N/m,
pulled, and released. What is the
period of the resulting oscillation?
(Unit = s)

Answers

Answer:

T= 0.6 sec

Explanation:

This problem bothers on the simple harmonic motion of a loaded spring

Given data

mass attached, m= 0-.675 kg

spring constant, k= 72.4 N/m

the period of oscillation can be solved for using the formula bellow

[tex]T= 2\pi \sqrt{\frac{m}{k} }[/tex]

Substituting the given data into the expression above we have

[tex]T= 2*3.142\sqrt{\frac{0.675}{72.4} }\\T= 6.284*\sqrt{0.0093 }\\T= 0.6[/tex]

T= 0.6 sec

Answer:

0.607

Explanation:

Trust me

can someone proofread my Big freeze theory of the universe? does it make sense?

Answers

Answer:

Yes great job it was well written!:)

A horizontal spring with spring constant 210 Nm is compressed by 20 cm and then used to launch a 250 g box across the floor. The coefficient of kinetic friction between the box and the floor is 0.23. What is the box's launch speed?

Answers

Answer:

ugmd = 1/2 kx²

d = (1/2 kx²) / (ugm)

= (1/2 * 250 N/m * (0.2 m)²) / (0.23 * 9.81 m/s² * 0.3 kg)

= 7.4 m

ugmd = 1/2 mv²

v = √2ugd

= √(2(0.23)(9.81 m/s²)(7.4 m)

= 5.8 m/s

Explanation:

The box's launch speed is 5.8 m/s.

What is energy?

Energy is the ability or capability to do tasks, such as the ability to move an item (of a certain mass) by exerting force. Energy can exist in many different forms, including electrical, mechanical, chemical, thermal, or nuclear, and it can change its form.

Given in question spring with spring constant 210 Nm is compressed by 20 cm and then used to launch a 250 g box across the floor,

ugmd = 1/2 kx²

d = (1/2 kx²) / (ugm)

= (1/2 * 250 N/m * (0.2 m)²) / (0.23 * 9.81 m/s² * 0.3 kg)

= 7.4 m

ugmd = 1/2 mv²

v = √2ugd

= √(2(0.23)(9.81 m/s²)(7.4 m)

= 5.8 m/s

The box's launch speed is 5.8 m/s.

To learn more about energy refer to the link:

brainly.com/question/1932868

 #SPJ5

Which of the following statements are true? (mark all that apply)
A) Adaptive optics corrects for atmospheric distortion by following the distortion of a bright star, possibly an artificial star created by a laser, and rapidly changing the shape of a mirror using computer-controlled actuators to compensate for the distortion.
B) Improvements in technology will eventually allow the entire electromagnetic spectrum to be observed from high mountaintop observatories.
C) X rays from astronomical objects can only be detected from telescopes in space or in high altitude rockets.
D) The best observing sites for optical telescopes are atop remote mountains.
E) Radio telescopes must be carried to high altitudes by balloons in order to detect this type of radiation.

Answers

Answer:

The answer(s) for this question are as followed: A, C, & D

Explanation:

I hope this helped, let me know if i missed any.

The three-dimensional arrangement of electron groups around the central atom is called ____.

A. Election-pair repulsion
B. Electronegativity
C. Geometric design
D. Electron-group geometry

Answers

Answer:

D. Electron - group geometry

Explanation:

Just did it boom THE BANK BUSTA WINS AGAIN

Can anyone tell me how to read a micrometer screw gauge I want very clear instructions.

Answers

Explanation:

Things you need to know:

Accuracy refers to the maximum error encountered when a particular observation is made.

Error in measurement is normally one-half the magnitude of the smallest scale reading.

Because one has to align one end of the rule or device to the starting point of the measurement, the appropriate error is thus twice that of the smallest scale reading.

Error is usually expressed in at most 1 or 2 significant figures.

Tape

Equipment: It is made up of a long flexible tape and can measure objects or places up to 10 – 50 m in length. It has markings similar to that of the rigid rule. The smallest marking could be as small as 0.1 cm or could be as large as 0.5 cm or even 1 cm.

How to use: The zero-mark of the measuring tape is first aligned flat to one end of the object and the tape is stretched taut to the other end, the reading is taken where the other end of the object meets the tape.

Ruler

Equipment: It is made up of a long rigid piece of wood or steel and can measure objects up to 100 cm in length. The smallest marking is usually 0.1 cm.

How to use: The zero-end of the rule is first aligned flat with one end of the object and the reading is taken where the other end of the object meets the rule.

Vernier Caliper

Equipment: It is made up of a main scale and a vernier scale and can usually measure objects up to 15 cm in length. The smallest marking is usually 0.1 cm on the main scale.

It has:

a pair of external jaws to measure external diameters

a pair of internal jaws to measure internal diameters

a long rod to measure depths

How to use: The jaws are first closed to find any zero errors. The jaws are then opened to fit the object firmly and the reading is then taken.

Micrometer Screw Gauge

Equipment: It is made up of a main scale and a thimble scale and can measure objects up to 5 cm in length. The smallest marking is usually 1 mm on the main scale (sleeve) and 0.01 mm on the thimble scale (thimble). The thimble has a total of 50 markings representing 0.50 mm.

It has:

an anvil and a spindle to hold the object

a ratchet on the thimble for accurate tightening (prevent over-tightening)

How to use: The spindle is first closed on the anvil to find any zero errors ( use the ratchet for careful tightening). The spindle is then opened to fit the object firmly (use the ratchet for careful tightening) and the reading is then taken.

hey help me plzzzzz i will mark brainliest​

Answers

Answer:

The answer to your question is given below.

Explanation:

Mechanical advantage (MA) = Load (L)/Effort (E)

MA = L/E

Velocity ratio (VR) = Distance moved by load (l) / Distance moved by effort (e)

VR = l/e

Efficiency = work done by machine (Wd) /work put into the machine (Wp) x 100

Efficiency = Wd/Wp x100

Recall:

Work = Force x distance

Therefore,

Work done by machine (wd) = load (L) x distance (l)

Wd = L x l

Work put into the machine (Wp) = effort (E) x distance (e)

Wp = E x e

Note: the load and effort are measured in Newton (N), while the distance is measured in metre (m)

Efficiency = Wd/Wp x100

Efficiency = (L x l) / (E x e) x 100

Rearrange

Efficiency = L/E ÷ l/e x 100

But:

MA = L/E

VR = l/e

Therefore,

Efficiency = L/E ÷ l/e x 100

Efficiency = MA ÷ VR x 100

Efficiency = MA / VR x 100

electronegativity increases when atoms ___
A.have a small atomic radius
B.are located in the right on the periodic table
C.are located on the left on the periodic table
D.have a large atomic radius

Answers

your answer is.....

D. have a large atomic radius

although they also increase going from left to right so if D is incorrect, B might be your answer. it depends on context of the lesson.

If 2N force is applied on 2 kg mass due east and same magnitude of force due west, thechange in velocity of the body in 2 sec is

Answers

Explanation:

F=m(v-u)/t

F=2N

m=2kg

t=2s

2=2(v-u)/2

cross multiply

2*2=2(v-u)

4=2(v-u)

4/2=v-u

v-u=2m/s

v-u is the change is velocity.

The change in velocity of the body in 2 sec is 2m/s

According to Newton's second law which states that the change in momentum of an object is directly proportional to the applied force.

Mathematically:

[tex]F \ \alpha \ (\dfrac{v-u}{t} )[/tex]

[tex]F = m (\dfrac{v-u}{t} )[/tex]

where:

m is the mass

(v - u) is the change in velocity

t is the time

F is the applied force

Given the following:

mass m = 2kg

time t = 2secs

Force F = 2N

Required

Change in velocity (v-u)

Substitute the given parameters into the expression shown above:

[tex]2=2(\dfrac{v-u}{2})\\ 2 \times 2=2(v-u)\\4=2(v-u)\\v-u=\dfrac{4}{2}\\v-u=2m/s\\[/tex]

Hence the change in velocity of the body in 2 sec is 2m/s.

Learn more here: https://brainly.com/question/3232705

(b) Calculate the momentum when a mass of 40kg is moving with a velocity of 20m/s in the forward
direction.

Answers

Explanation:

momentum = mass x velocity

momentum = 40 x 20 = 800kgm/s

Answer:

800kgm/s

Explanation:

momentum= mass×velocity

= 40×20

= 800kgm/s

Other Questions
A Huge water tank is 2m above the ground if the water level on it is 4.9m high and a small opening is there at the bottom then the speed of efflux of non viscous water through the opening will be Ethylene, a gas found in nature, is commonly used to ripen bananas and other fruits. Which compound is ethylene?H2C CH20 Which is NOT a benefit of good cardiovascular health? stronger bone mass increasing your self-esteem the ability to manage stress improvement in appearance Do you know best way to know WiFi password which you are connected to? Alice is building a caterpillar habitat for some caterpillars she found in her back yard. She plans to cover all sides of the habitat with screen so the caterpillars get plenty of fresh air. What is the total amount of screen that Alice will need for her habitat? please help :) Which number is less than 2.167 10 to the 4 power? A. 9,978 B. 1.1 x 10 to the 6 power C. 56,344,000 D. 2.468 10 to the 5 power Dante is 2-years old. His mother took him to the doctor and discovered that he had gained 5 pounds and grown 2 inches since his last physical exam. This is an example of the role of_________ processes in development. What is the center of the circle with the equation (x-1)^2 + (y+3)^2= 9? a (1,3) b (-1,3) c (-1,-3) d (1,-3) Easy Spanish EASY POINTS :D Point C is on the graph of the function y = x2 3. Its x-coordinate is 4. Which ordered pair gives the location of point C? A.(4, 42 3) B.(4, 2 + 3) C.(42, 42 3) D.(4, 42) 25 POINTSExamine the following solution to a conversion problem. Do you see a mistake? If so, identify the location of the first mistake and explain why it is incorrect.Original Problem: Convert 3.25 kg to mg(1) 3.25 kg(2) 1 kg = 1000 g(3) 1000 mg = 1g= (4) 3.25 mgA) The conversion is not possible.B) The first problem occurs in column (1). The problem should begin with mg.C) The first problem occurs in column (2). 1 kg is not equal to 1000 g, so that should not be used as the conversion factor.D) The first problem occurs in column (2). The conversion factor is upside down (grams should be on top, and kg should be on bottom).E) The first problem occurs in column (4). The multiplication and division was performed incorrectly.F) No mistakes.Thanks a bunch! A spaceship is moving past Earth at 0.99c. The spaceship fires two lasers. Laser A is in the same direction it is traveling, and Laser B is in the opposite direction. How fast will the light from each laser be traveling according to an observer on Earth? What is the total energy change for the following reaction:CO+H2O-CO2+H2 Stimulants used to treat conditions like ADHD and narcolepsy can complicate which of the following health conditions? Local law defines the speed limit as 45 miles per hour. Police stop a man traveling 67 miles per hour. The officer gives him a ticket for violating the speed limit law. Which characteristic of rule of law does this situation best illustrate? A room with 3.1-m-high ceilings has a metal plate on the floor with V = 0V and a separate metal plate on the ceiling. A 1.1g glass ball charged to 4.7 nC is shot straight up at 4.8 m/s from the floor level. How high does the ball go if the ceiling voltage is +3.0x10^6V? The following data concerns a proposed equipment purchase: Cost $ 144,000 Salvage value $ 4,000 Estimated useful life 4 years Annual net cash flows $ 46,100 Depreciation method Straight-line Assuming that net cash flows are received evenly throughout the year, the accounting rate of return is (ignore income taxes): What happens when white light shines through a translucent, red, glass window? a) All colors of light except red are transmitted through the glass. b) Red light is transmitted through and reflected by the glass c) Red light is absorbed by the glass d) all colors except red are reflected by the glass A hot air balloon competition requires a balloonist to drop a ribbon onto a target on the ground. Initially the hot air balloon is 50 meters above the ground and 100 meters from the target. The wind is blowing the balloon at v= 15 meters/sec on a course to travel directly over the target. The ribbon is heavy enough that any effects of the air slowing the vertical velocity of the ribbon are negligible. How long should the balloonist wait to drop the ribbon so that it will hit the target? who is the main character in the book hobbit