In a test run, a certain car accelerates uniformly from zero to 20.4 m/s in 2.60 s.

Required:
a. What is the magnitude of the cars acceleration?
b. How long does it take the car to change speed from 10.0 m/s to 20 m/s.
c. Will doubling the time always double the change in speed? why?

Answers

Answer 1

Answer:

(a) The acceleration is 7.85 m/s²

(b) It takes the car to change speed from 10.0 m / s to 20 m / s in a time of 1.27 seconds.

(c) Doubling the time will double the change in velocity if the acceleration is kept constant.

Explanation:

(a)  Acceleration is the physical quantity that measures the rate of change of velocity with time. That is, acceleration relates changes in speed with the time in which they occur, that is, it measures how fast the changes in speed are.

The average acceleration is calculated using the following expression:

[tex]a=\frac{vf-vi}{t}[/tex]

where a is the acceleration, vf is the final velocity, vi is the initial velocity and t is the time.

In this case:

vf= 20.4 m/svi=0 m/st= 2.60 s

Replacing:

[tex]a=\frac{20.4 \frac{m}{s} - 0\frac{m}{s} }{2.60 s}[/tex]

a= 7.85 m/s²

The acceleration is 7.85 m/s²

(b) In this case you know:

a= 7.85 m/s²vf= 20 m/svi= 10 m/s

Replacing:

[tex]7.85 \frac{m}{s^{2} } =\frac{20 \frac{m}{s} - 10\frac{m}{s} }{t}[/tex]

and solving you get:

[tex]t=\frac{20 \frac{m}{s} - 10\frac{m}{s} }{7.85 \frac{m}{s^{2} } }[/tex]

t=1.27 s

It takes the car to change speed from 10.0 m / s to 20 m / s in a time of 1.27 seconds.

(c)  Being:

[tex]a=\frac{vf-vi}{t}[/tex]

Then:

a*t= vf - vi

vf - vi represents the change in velocity. You can see that, if a (acceleration) is constant, then (vf - vi) is directly proportional to the time t: therefore, if t doubles, the change in velocity doubles as well.

In other words, doubling the time will double the change in velocity if the acceleration is kept constant.


Related Questions

Mental processes refers to

overt actions and reactions.

only animal behavior.

internal, covert processes.

outward behavior.

Answers

Internal,covert processes

If a net horizontal force of 0.8 N is applied to a toy whose mass is 1.2 kg, acceleration is?

Answers

Hello!

[tex]\large\boxed{a = \frac{2}{3}m/s^{2}}[/tex]

Use the equation F = m · a to solve. We are given the force (N) and mass (kg), so we can solve for the acceleration by plugging in the given values:

0.8 = 1.2a

0.8 / 1.2 = a

a = 2/3 m/s²

The energy of a photon is ________ proportional to its wavelength.

Answers

Answer:

The amount of energy is directly proportional to the photon's electromagnetic frequency and thus, equivalently, is inversely proportional to the wavelength. The higher the photon's frequency, the higher its energy. Equivalently, the longer the photon's wavelength, the lower its energy.

Explanation:

Plz mark brainliest thanks

PLEASE HELP!!!!
Suppose a tractor was moving forward at 6.0 m/s. It runs into a pile of hay and is
brought to a stop in 1.1 s. If the tractor had a mass of 2550 kg, with what force did
the pile of hay stop the tractor?
A. -5.5N
B. -14000N
C. 15000N
D. -15000N
E. -0.0021N
F. -0.000072

Answers

Answer:

B )-14000N

Explanation:

F=mv-mu

t

F =2550(0)-2550(6)

1.1

F = -13909.09

approximately -14000N

Suppose a tractor was moving forward at 6.0 m/s. It runs into a pile of hay and is brought to a stop in 1.1 s. If the tractor had a mass of 2550 kg, the force did the pile of hay stop the tractor 14000N

What are the types of force ?

Force can be a unit of  pushing or pulling of any object which result   from the object’s interaction or movement, without applying force the objects can not be moved, can be stopped or change the direction.

Force is a  quantitative parameter between two physical bodies, means an object and its environment, there are various  types of forces in nature.

If an object present in its moving state will be either static or motion, the position of the object will be changed if it is pushed or pulled and The external push or pull upon the object is mainly called as Force.

The contact force  that occurs when we apply some effort on an object such as Spring Force, Applied Force, Air Resistance Force, Normal Force, Tension Force, Frictional Force

Non-Contact forces are the type of forces that occur from a distance  such as Electromagnetic Force, Gravitational Force, Nuclear Force

F=mv-mu

t

F =2550(0)-2550(6)

1.1

F = -13909.09

approximately -14000N

For more details Force, visit

brainly.com/question/13691251

#SPJ2

define alpha and beta​

Answers

alpha is the excess return on an investment after adjusting for market related volatility and random fluctuations.

beta is a measure of volatility relative to a benchmark ,such as the S&P 500.

Explanation:

alpha and beta are two different parts of an equation used to explain the performance of stocks and investments funds. But in maths alpha and beta is the Greek alphabet

A child blows a leaf from rest straight up in the air. the leaf has a constant upward acceleration of magnitude 1.0 m by s square. how much time does it take the leaf to displace 1.0m upwards?

Answers

Answer:

√2

Explanation:

From the question, we're given that the

Acceleration of the leaf is 1 m/s²

Change in displacement of the leaf is 1 m/s.

Again, from the question, we can tell that the initial velocity u = 0, since the object starts at rest

Now, to solve this, we don't the equation of motion to ur

S = ut + 1/2at², substituting the whole parameters, we then have

1 = 0 * t + 1/2 * 1 * t²

1 = 1/2 * t²

t²/2 = 1

t² = 2

t = √2 seconds

Therefore the time it takes the leaf to dislodge is 2 seconds

What acceleration will you give a 22.4 kg box if you push it with a force of 83.1N

Answers

Answer:

mass =22.4kg

force=83.1N

a=?

f=ma

a=f/m

a=83.1/22.4

a=3.70m/s^2

For an object like a planet, with a typical temperature of a few hundred kelvin, what kind of blackbody radiation would it principally emit

Answers

Answer:

Low-temperature blackbody

Explanation:

There are 3 types of blackbody temperatures.

Low-temperature blackbody

High temperature extended area blackbody

High-temperature cavity blackbody

A Low-temperature blackbody is a type of black body radiation that has the range of -40° C to 175° C, typically between 233 K and 448 K. A perfect fit for the temperature range mentioned in the question, "a few hundred Kelvin". Therefore, it's the kind of blackbody temperature that the object would emit.

derive an expression for torque experiend by an electric dipole placed in a uniform electric field​

Answers

Answer:

The torque τ on an electric dipole with dipole moment p in a uniform electric field E is given by τ = p × E where the "X" refers to the vector cross product. Ref: Wikipedia article on electric dipole moment.

Explanation:

An object has an average acceleration of + 6.24 m/s ^ 2 for 0.300 s . At the end of this time the object's velocity is + 9.31 m/s . What was the object's initial velocity?

Answers

Answer:

initial velocity = 7.44 m/s   (3 s.f.)

Explanation:

a = 6.24 m/s²     t = 0.300 s     v = 9.31 m/s       u = ?

                               v = u + at

                       9.31 = u + (6.24 x 0.300)

                             9.31 = u + 1.872

                                    u = 7.438

                                    = 7.44 m/s       (3 s.f.)

Hope this helps!

Two particles are separated by 0.38 m and have charges of -6.25 x 10-°C and 2.91 x 10-°C. Use Coulomb's law to predict the force between the particles if the distance is cut in half. The equation for Coulomb's law is F = kqi 42, and the constant, k, equals 9.00 x 109 Nm2/C2 2

Answers

Answer:

-4.35 × 10^-6 N

Explanation:

i just answered it on ap3x :)

Sugar crystals enter a dryer at the rate of 1000 kg h-1 and at 20% w.b. moisture content. They leave the dryer at 3% w.b. moisture content. If the drying process requires 3000 kJ kg-1 of water removed, estimate the amount of heat required per hour and the rate of dry crystals out of the dryer.

Answers

Answer:

The dryer evaporate 200 - 24.74 kg of water per hour

To remove 1kg of water it need 3000 K J

So to remove, 175.26 Kg

it need 5.257x [tex]10^{5}[/tex] KJ of heat per hour.

Explanation:

In one hour, the amount of sugar entering = 1000 kg

w.b moisture content is defined as,

weight of water / weight of water + weight of dry

[tex]W_{w}[/tex]/[tex]W_{w}[/tex] + [tex]W_{d}[/tex] x 100

[tex]W_{w}[/tex] + [tex]W_{d}[/tex] = 1000 kg when entering

it has 20% moisture content when entering

[tex]W_{w}[/tex] = 0.2 x 1000 = 200 kg

when leaving it has 3% moisture content then weight of dry material

[tex]W_{d}[/tex] = 1000 - 200 = 800 Kg

[tex]\frac{W_{w}^{'} }{W_{w}^{'} + W_{d}^{'} }[/tex] = 0.03

[tex]\frac{W_{w}^{'} }{W_{w}^{'} + 800 }[/tex] = 0.03

[tex]W_{w} ^{'}[/tex] = 0.03 x [tex]W_{w} ^{'}[/tex] + 0.03 x 800

[tex]W_{w} ^{'}[/tex] = 24.74 kg

When leaving the dryer, the crystals has total weight of the water = 24.74 kg per hour.

The dryer evaporate 200 - 24.74 kg of water per hour

To remove 1kg of water it need 3000 K J

So to remove, 175.26 Kg

it need 5.257x [tex]10^{5}[/tex] KJ of heat per hour.

A 15.0kg block is dragged over a rough, horizontal surface by a 70.0-N force acting at 20.0 degrees above the horizontal. The block is displaced 5.0 m, and the coefficient of kinetic friction is 0.3.

a. Draw a free body diagram. Draw your coordinate system and label the axes.
b. Calculate the work done on the block by the 70 N force.
c. Calculate the work done on the block by the normal force.
d. Calculate the work done on the block by the gravitational force.
e. Calculate the work done on the block by the force of friction.

Answers

Answer:

[tex]W=70 * 5cos20 = 328.89 J[/tex]

[tex]W_n = 0[/tex]

[tex]W_g=0[/tex]

[tex]W_f= -184.59J[/tex]

Work done is 0

Explanation:

From the question we are told that

Weight of block =15.0kg

Force acting on the block = 70.0N

At an angle of 20 degree

Displacement of block is 5m

Coefficient of kinetic friction 0.3

b) Generally work done by force is give by [tex]W=fdcos \theta[/tex]

therefore

      [tex]W=70 * 5cos20 = 328.89 J[/tex]

c) there is no work done by the normal force in this scenario because

normal force in this case is perpendicular to the displacement of the motion

       [tex]W_n = 0[/tex]

d) The displacement in the vertical direction is 0

Therefore the gravitational work done is 0  [tex]W_g=0[/tex]

e)Generally in finding work done by friction we first find frictional force

Mathematically the equation for frictional force is given [tex]f = \alpha N[/tex]

Given that

       [tex]N=mg-Fsin20[/tex]

       [tex]N= 15.0*9.8 - 70 sin20[/tex]

       [tex]N=123 N[/tex]

       [tex]f=0.3* 123.06 = 36.92N[/tex]

Mathematically solving to get work done by frictional force [tex]W_f[/tex]

        [tex]W_f= -fd\\W_f = -36.92 * 5[/tex]

         [tex]W_f= -184.59J[/tex]

the frictional force work done is  [tex]W_f= -184.59J[/tex]


A circuit with a 12 V battery and lamp has a current of 3 A. What is the resistance of the lamp?

Answers

chicken is the resistance of the lamp

A thin-walled vessel of volume V contains N particles which slowly leak out of a small hole of area A. No particles enter the volume through the hole. Find the time required for the number of particles to decrease to N/2. Express your answer in terms of A, V, and v.

Answers

Answer:

    [tex]\frac{V}{2av}[/tex]

Explanation:

From the question we are told that

Volume V

Contains N particles

Leaks from a small hole of area A

Generally the equation for Flow rate is given as

Volume Flow Rate  [tex]V_r = A * v[/tex]

Mathematically we find the  time taken to flow half way which is given by

          [tex]\frac{(V/2)}{A*v}[/tex]

Therefore the  time taken is

           [tex]\frac{V}{2av}[/tex]

For the following types of electromagnetic radiation, how do the wavelength, frequency, and photon energy change as one goes from the top of the list to the bottom?

a. radio waves
b. infared radiation
c. visible light
d. ultraviolet radiation
e. gamma radiation

Answers

Answer:

Wavelength, frequency and the photon energy changes as the one goes across the ranges of the electro-magnetic radiations.

Explanation:

Electro-magnetic radiations may be defined as the form of energy that is radiated or given by the electro-magnetic radiations. The visible light that we can see is the one of the electro-magnetic radiations. Other forms are the radio waves, gamma waves, UV rays, infrared radiations, etc.

The wavelength of the radiations decreases as we go from a. radio waves -- b. infrared radiation -- c. visible light -- d. ultraviolet radiation -- e. gamma radiation.

The frequency of the radiations increases when we move from a. radio waves -- b. infrared radiation -- c. visible light -- d. ultraviolet radiation -- e. gamma radiation.

The photon energy of the radiations increases when we move from a. radio waves -- b. infrared radiation -- c. visible light -- d. ultraviolet radiation -- e. gamma radiation.

An astronaut weighing 190 lbs on Earth is on a mission to the Moon and Mars.

Required:
a. What would he weigh in newtons when he is on the Moon?
b. How much would he weigh in newtons when he is on Mars, where the acceleration due to gravity is 0.38 times that on Earth?

Answers

Answer:

The weight is defined as:

W = m*g

where:

m = mass

g = gravitational acceleration.

We know that in Earth the astronaut weights 190 lb-f (this is force, not mass, the correct unit here is 190 lb*m/s^2)

then:

190 lb*m/s^2 = m*9.8m/s^2

(190 lb*m/s^2)/(9.8m/s^2) = 19.39 lb

Now we know the mass of the astronaut.

a) wieght on the moon in Newtons.

Newtons uses kilograms as the units of mass, then we need to rewrite the mass of the astronaut in kg.

we know that 1lb = 0.454 kg

Then 19.39 lb is equal to: 19.39*0.454 kg = 8.8 kg

We know that the acceleration due to gravity on the Moon is one-sixth that on Earth.

then: g = (9.8m/s^2)/6

And the weight of the astronaut in the moon will be:

W = 8.8 kg*(9.8m/s^2)/6 = 14.37 N

b) The weight on mars, where the acceleration due to gravity is 0.38 times that on Earth, we have:

g = (9.8m/s^2)*0.38

then the weight will be:

W = 8.8kg*(9.8m/s^2)*0.38 = 32.77 N

Bob, of mass m, drops from a tree limb at the same time that Esther, also of mass m, begins her descent down a frictionless slide. If they both start at the same height above the ground, which of the following is true about their kinetic energies as they reach the ground?
A) Bob's kinetic energy is greater than Esther's.B) Esther's kinetic energy is greater than Bob's.C) They have the same kinetic energy.D) The answer depends on the shape of the slide.

Answers

Answer:

Explanation:

They have the same kinetic energy

A truck covers 40.0 m in 9.50 s while uniformly slowing down to a final velocity of 2.75 m/s.

a. Find its original speed.
b. Find its acceleration.

Answers

Explanation:

Given that,

Distance covered, d = 40 m

Time, t = 9.5 s

Final velocity, v = 2.75 m/s

(a) Let u be the original speed of the truck. We can find it using first equation of motion.

[tex]v=u+at\\\\2.75=u+2.75\times 9.5\\\\2.75-26.125=u\\\\u=-23.375\ m/s[/tex]

(b) Acceleration = rate of change of velocity

[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{2.75-(-23.375)}{9.5}\\\\=2.75\ m/s^2[/tex]

So, the original speed is -23.375 and acceleration is 2.75 m/s².

A solid is 5 cm tall, 3 cm wide, and 2 cm thick. It has a mass of 129 g. What is its
density?

Answers

Answer:

4.3 g/cm³ or 4.3g/cc

Explanation:

Volume(V) = Height × Length × Width

= 5cm × 3cm × 2cm

= 30cm³

Mass(m) = 129gram

So,

Density = m/V

= 129g/30cm³

= 4.3g/cc or 4.3g/cm³

A hockey player strikes a puck that is initially at rest. The force exerted by the stick on the puck is 975 N, and the stick is in contact with the puck for 0.0049 s.
(a) What is the impulse imparted by the stick to the puck.
___________ kg m/s
(b) What is the speed of the puck (m= 1.67 kg)just after it leaves the hockey stick?
____________ m/s

Answers

Explanation:

Given that,

The force exerted by the stick on the puck is 975 N

The stick is in contact with the puck for 0.0049 s

Initial speed of the puck, u = 0 (at rest)

(a) We need to find the impulse imparted by the stick to the puck.

Impulse = Force × time

J = 4.7775 kg-m/s

(b) Mass of the puck, m = 1.76 kg

We need to find the speed of the puck just after it leaves the hockey stick.

Let the speed be v.

As impulse is equal to the change in momentum.

[tex]J=m(v-u)\\\\4.7775=1.67(v-0)\\\\v=\dfrac{4.7775}{1.67}\\\\v=2.86\ m/s[/tex]

So, when the puck leaves the hockey stick its speed is 2.86 m/s.

A basketball is rolling rightward onto the court with a speed of 4.0 m/s and slows down with a consta leftward acceleration of magnitude 0.50 m/s^2 over 14 m.
What is the velocity of the basketball after rolling for 14 m?
a. 2.0 m/s
b. 5.5 m/s
c. 7.5 m/s
d. 1.4 m/s

Answers

Answer:

d. 1.4 m/s

Explanation:

Given;

initial velocity of the `basketball, u = 4.0 m/s

acceleration of the basketball, a = -0.5 m/s² (leftward)

distance the basketball traveled, d = 14 m

the final velocity of the basketball, v = ?

(this final velocity should be less than the initial velocity since the ball is slowing down at a constant rate)

Apply the following the kinematic equation;

v² = u² + 2ad

v² = 4² + 2(-0.5)14

v² = 16 - 14

v² = 2

v = √2

v = 1.41 m/s

Therefore, the final velocity of the basketball is 1.4 m/s.

Calculate the escape velocity
the moon's surface given that a man on the moon has 1/6 his weight on earth​

Answers

Answer:

v = 2.38 × 10³ m/s

Explanation:

Escape velocity, v = √(2gR) where g = acceleration due to gravity on planet and R = radius of planet.

Since it is given that the weight of the man on the moon is 1/6 his weight on earth, and g' = acceleration due to gravity on moon and g = acceleration due to gravity on earth and m = mass of man,

mg' = mg/6

g' = g/6

Since g = 9.8 m/s²,

g'= 9.8 m/s² ÷ 6

g' = 1.63 m/s²

The escape velocity of the moon is thus  v = √(2g'R) where R = radius of moon = 1.737 × 10⁶ m.

Substituting these into v, we have

v = √(2g'R)

v = √(2 × 1.63 m/s² × 1.737 × 10⁶ m)

v = √[5.663 × 10⁶ (m/s)²]

v = 2.38 × 10³ m/s

You work at a garden store for the summer. You lift a bag of fertilizer with a force of 112 N, and it moves upward with an acceleration of 0.790 m/s^2.

a. What is the mass of the fertilizer bag?
b. How much does the fertilizer bag weigh?

Answers

Given :

Force provided, F = 112 N.

Acceleration of the bag, a = 0.79 m/s².

To Find :

a. What is the mass of the fertilizer bag?

b. How much does the fertilizer bag weigh?

Solution :

We know, force is given by :

F = ma

m = F/a

m = 112/0.79 kg

m = 141.77 kg

Now, weight is given by :

W = mg

W = 141.77 × 9.8 N

W = 1389.35 N

Therefore, the mass of fertilizer bag is 141.77 kg and weight us  1389.35 N.

a 150kg roller coaster SITTING ON THE TOP OF A 200M HILL HAS HOW MUCH POTETNTIAL ENERGY

Answers

Answer:

Epot = 294300 [J]

Explanation:

Potential energy is defined as the product of mass by height by gravitational acceleration. The height is measured with respect to the reference level. At this reference level the potential energy is equal to zero.

[tex]E_{pot}=m*g*h\\[/tex]

where:

m = mass = 150 [kg]

g = gravity acceleration [m/s²]

h = elevation = 200 [m]

[tex]E_{pot}=150*9.81*200\\E_{pot}=294300 [J][/tex]

in how many days the life cycle of honeybee complete​

Answers

Honey bees develop in four distinct life cycle phases: egg, larva, pupa, and adult. The total development time varies a bit among the three castes of bees, but the basic miraculous process is the same: 24 days for drones, 21 days for worker bees, and 16 days for queens.
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