Two stones are thrown from the top edge of a building with a speed of 20 m/s, one straight down and the other straight up. The first one hits the street in a time t1. How much later is it before the second stone hits

Answers

Answer 1

Answer:

Second stone hist at 4.08 s later.

Explanation:

The second stone straight up, so we need to find the rise and descent time.

[tex]v_{f}=v_{i}-gt[/tex]

At the top, the final speed is 0 and t is the rise time.

[tex]0=20-gt_{r}[/tex]

[tex]t_{r}=\frac{20}{9.81}[/tex]

[tex]t_{r}=2.04 s[/tex]

Let's recall that the rise time is equal to the descent time.

So the total time of the stone will be

[tex]t_{t}=4.08 s[/tex]

Now, the second stone hits the street in t2 = 4.08 s + t1 s

But we just need the time after the first stone hist the street. So we just subtract the time t1 to the second time t2, which means t2 = 4.08 s.

Therefore stone hist at 4.08 s later.

Answer 2

The second stone hits the wall 4.08 seconds later.

To solve this question, we will use the equation of motion. In particular, the first equation of motion which states that;

v = u + at, where

v = the final velocity

u = the initial velocity

a = acceleration of gravity

t = time taken by the stone.

From the question, we're told that the stone is thrown with a speed of 20 m/s, which is the initial velocity. And a final velocity, v of 0 m/s. Using a constant of 9.81 for acceleration of the stone. We have,

0 = 20 - 9.81 × t

20 = 9.81t

t = [tex]\frac{20}{9.81}[/tex]

t = 2.039or 2.04 seconds.

Assuming that the time taken to ascent = time taken to descent, this means that the total time taken will be 2.039 + 3.039 = 4.078 seconds or 4,08 seconds.

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Related Questions

Which is greater, the energy of one photon of orange light or the energy of one quantum ofradiation having a wavelength of 3.36 * 10^-9

Answers

The question is incomplete, here is the complete question:

Which is greater, the energy of one photon of orange light or the energy of one quantum of radiation having a wavelength of [tex]3.36\times 10^{-9}m[/tex]

Answer: The energy of one quantum of radiation having wavelength [tex]3.36\times 10^{-9}m[/tex] is greater than the energy of 1 photon of orange light.

Explanation:

To calculate the energy of one photon, we use the Planck's equation:

[tex]E=\frac{N_Ahc}{\lambda}[/tex]

where,

E = energy of radiation

[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}mol^{-1}[/tex]

h = Planck's constant = [tex]6.626\times 10^{-34}Js[/tex]

c = speed of light = [tex]3\times 10^8 m/s[/tex]

[tex]\lambda}[/tex] = wavelength of radiation

For orange light:

For 1 photon, the term [tex]N_A[/tex] does not appear

[tex]\lambda}[/tex] = 620 nm = [tex]620\times 10^{-9}m[/tex]             (Conversion factor: [tex]1nm=10^{-9}m[/tex] )

Putting values in above equation, we get:

[tex]E=\frac{6.626\times 10^{-34}Js\times 3\times 10^8m/s}{620\times 10^{-9}m}\\\\E=3.206\times 10^{-19}J[/tex]

For one quantum of radiation:

[tex]\lambda}[/tex] = [tex]3.36\times 10^{-9}m[/tex]

Putting values in above equation, we get:

[tex]E=\frac{6.022\times 10^{23}mol^{-1}\times 6.626\times 10^{-34}Js\times 3\times 10^8m/s}{3.36\times 10^{-9}m}\\\\E=3.56\times 10^{7}J/mol[/tex]

Hence, the energy of one quantum of radiation having wavelength [tex]3.36\times 10^{-9}m[/tex] is greater than the energy of 1 photon of orange light.

A small lead ball, attached to a 1.10-m rope, is being whirled in a circle that lies in the vertical plane. The ball is whirled at a constant rate of three revolutions per second and is released on the upward part of the circular motion when it is 1.3 m above the ground. The ball travels straight upward. In the absence of air resistance, to what maximum height above the ground does the ball rise

Answers

Answer:

1.84 m

Explanation:

For the small lead ball to be balanced at the tip of the vertical circle just before it is released, the reaction force , N equal the weight of the lead ball W + the centripetal force, F. This normal reaction ,N also equals the tension T in the string.

So, T = mg + mrω² = ma where m = mass of small lead ball, g = acceleration due to gravity = 9.8 m/s², r = length of rope = 1.10 m and ω = angular speed of lead ball = 3 rev/s = 3 × 2π rad/s = 6π rad/s = 18.85 rad/s and a = acceleration of normal force. So,

a = g + rω²

= 9.8 m/s² + 1.10 m × (18.85 rad/s)²

= 9.8 m/s² + 390.85 m/s²

= 400.65 m/s²

Now, using v² = u² + 2a(h₂ - h₁)  where u = initial velocity of ball = rω = 1.10 m × 18.85 rad/s = 20.74 m/s, v = final velocity of ball at maximum height = 0 m/s (since the ball is stationary at maximum height), a = acceleration of small lead ball = -400.65 m/s² (negative since it is in the downward direction of the tension), h₁ = initial position of lead ball above the ground = 1.3 m and h₂ = final position of lead ball above the ground = unknown.

v² = u² + 2a(h₂ - h₁)

So, v² - u² = 2a(h₂ - h₁)

h₂ - h₁ =  (v² - u²)/2a

h₂ =  h₁ + (v² - u²)/2a

substituting the values of the variables into the equation, we have

h₂ =  1.3 m + ((0 m/s)² - (20.74 m/s)²)/2(-400.65 m/s²)

h₂ =  1.3 m + [-430.15 (m/s)²]/-801.3 m/s²

h₂ =  1.3 m + 0.54 m

h₂ =  1.84 m

A person runs up 33 stairs of height 0.25 m. The person weighs 599.85 N. How much energy does it take for the person to reach the top of the stairs? I need the answer ASAP

Answers

Answer:

149.96J

Explanation:

Given parameters:

Number of stairs = 33

Height  = 0.25m

Weight  = 599.85N

Unknown:

Energy the person takes to reach the top  = ?

Solution:

To solve this problem;

  The energy it takes is given as:

          Energy  = weight x height

          Energy  = mass x gravity x height

Now,

  Insert the given parameters and solve;

        Energy  = 599.85 x 0.25  = 149.96J

is college football playoffs the best way to determine the national champion?

Answers

Answer:

No it is Not because win ratio is differs say Ohio only won 7 out of 7 games and e

was in the playoffs while Alabama won 11 out of 11 games so it is harder to win 11 out of 1a games and it is easier to win 7 out of 7

Explanation:  would like brainliest but u don’t have to

A 146N force is needed to pull a 350 N block across a horizontal surface at a constant speed by a rope making an angle of 50 degrees with the floor. Find the coefficient of friction.

Answers

Answer:

F = force

f = friction

u = coefficient of friction

R = normal reaction force

a = Acceleration

m = mass of block

g = gravity

f = uR

F = Ma

Say the block is moving to the right.

The 146N force thus acts to the right, and the friction force to the left, since it resists movement.  

The 146N force acts to the right, but the horizontal component of it is 146 cos 50  = 93.84: So this is the force to the right.

Since F = uR and we're trying to find u, we need both F and R. R is easy to get since it is just m x g. This is in fact already given as the weight 350N. So R = 350.

The block is moving at a constant speed, so the force to the right must = the force to the left.

F = ma, so 93.84 - f = (350/g) x 0

This means f must be 93.84 also.  

so  we have f = uR,  

      93.84 = u x 350

so u = 0.268 or  

0.27 to 2dp.  

Hope you understand this.

Explanation:

The coefficient of friction is 0.26 if the 46N force is needed to pull a 350 N block across a horizontal surface at a constant speed by a rope making an angle of 50 degrees with the floor.

What is the friction force?

It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N). Mathematically it is defined as the product of the coefficient of friction and normal reaction.

We know:

f = uR

Where f is the friction force and u is the coefficient of friction, R is the normal reaction force.

The horizontal component of 146N is:

F' = 146cos50°

F' = 93.84 N

Since F  = mass×acceleration

Because the block is traveling at a constant speed, the right-hand force must equal the left-hand force.

F' = f = 93.84 N

93.84 = u x 350   (R = 350N)

u = 0.26

Thus, the coefficient of friction is 0.26 if the 46N force is needed to pull a 350 N block across a horizontal surface at a constant speed by a rope making an angle of 50 degrees with the floor.

Learn more about the friction force here:

https://brainly.com/question/1714663

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Why could it be argued that the respiratory system is most critical to sustaining life?

Answers

Explanation:

Energy is the most important ingredient for life. Organisms use energy in diverse ways. Scientifically, energy is defined as the ability to do work. Without this ability, organisms would not exist.

So, the most important process is one that can furnish the body with energy.

The respiratory system happens to be the one that furnishes the body with energy. During respiration, the energy needs of the body is met by series of processes. Oxygen is taken in and use to liberate calories from chemical substances packed with energy. So, without respiration, the bodily energy demands will not be met.

What can we conclude from observing an attractive force between a positively charged rod and some object

Answers

Answer: that the object is negatively charged.

Explanation:

We know that the force between objects that have the same type of charge is a repulsive force, while for objects with an opposite charge, the force is attractive.

In this case, we know that we have an attractive force between an object and a positively charged rod.

Then the only conclusion we can take in this situation is that the object is negatively charged.

An energy source forces a constant current of 2A to flow through a light bulbfilament for twenty seconds. If 4.6 kJ is given off in the form of light and heatenergy, calculate the voltage drop across the bulb.

Answers

Answer:

The voltage drop across the bulb is 115 V

Explanation:

The voltage drop equation is given by:

[tex]V=\frac{\Delta W}{\Delta q}[/tex]

Where:

ΔW is the total work done (4.6kJ)

Δq is the total charge

We need to use the definition of electric current to find Δq

[tex]I=\frac{\Delta q}{\Delta t}[/tex]

Where:

I is the current (2 A)

Δt is the time (20 s)

[tex]2=\frac{\Delta q}{20}[/tex]

[tex]q=40 C[/tex]

Then, we can put this value of charge in the voltage equation.

[tex]V=\frac{4600}{40}=115 V[/tex]

Therefore, the voltage drop across the bulb is 115 V.

I hope it helps you!

If a man traveled to a different planet

Answers

Answer:

He would be in space.

Explanation:

Answer: What would happen if a human traveled to Uranus?

As an ice giant, Uranus doesn't have a true surface. The planet is mostly swirling fluids. While a spacecraft would have nowhere to land on Uranus, it wouldn't be able to fly through its atmosphere unscathed either. The extreme pressures and temperatures would destroy a metal spacecraft.

Explanation:

Brainliest brainliest help help help mememememememme

Answers

Answer:

????????????????????,

Explanation:

I need points sorry

Answer:

honestly this was so long ago can i get brainliest i need 2 more until i am at expert level

Explanation:

A hammer strikes a nail with a 10 N force for 0.01 seconds. Calculate the impulse of the hammer.

Answers

Answer:

0.1Ns

Explanation:

Impulse is the product of Force and time

Impulse = Force * Time

Given

Force = 10N

Time = 0.01s

Substitute into the formula

Impulse = 10 * 0.01

Impulse = 10 * 1/100

Impulse = 10/100

Impulse = 0.1Ns

hence the impulse of the hammer is 0.1Ns

The human nervous system can propagate nerve impulses at about 102 m>s. Estimate the time it takes for a nerve impulse to travel 2 m from your toes to your brain.

Answers

Answer:

t = 0.196 s

Explanation:

The speed of a pulse is determined by the characteristics of the medium, its density and its resistance to stress, as long as these remain the speed will be constant for which we can use the kinetic expressions of the uniform movement

          v = x / t

          t = x / v

calculate

          t = 2/102

          t = 0.196 s

A motorcycle moving 18.8 m/s has
57800 J of KE. What is its mass?

Answers

Answer:

m = 327.07 kg

Explanation:

Given that,

Kinetic energy of a motorcycle, E = 57800 J

Velocity of the motorcycle, v = 18.8 m/s

We need to find the mass of the motorcycle. The kinetic energy of an object is given by :

[tex]E=\dfrac{1}{2}mv^2[/tex]

m is mass

[tex]m=\dfrac{2E}{v^2}\\\\m=\dfrac{2\times 57800 }{(18.8)^2}\\\\m=327.07\ kg[/tex]

So, the mass of the motorcycle is 327.07 kg.

If an ice cube has a mass of 5g and is left in the sun in a beaker, what will happen to its mass?​

Answers

Answer:

The mass remains the same

Explanation:

An ice cube of mass 5g left in the sun in a beaker will have no mass difference.

For this system, mass is conserved.

The ice cube begins to melt and the state changes. The state change is from solid to liquid. Since no mass is loss, the mass of the liquid formed and the ice will remain the same. In retrospect, this physical change ensures that mass is conserved.

An electron traverses a vacuum tube with a length of 2 m in 2 X 10- 4
sec. What is the average speed of the
electron during this time?

Answers

Answer:

Average speed = 10,000 m/s

Explanation:

Given the following data;

Distance = 2m

Time = 0.0002secs

To find the average speed;

Average speed = distance/time

Average speed = 2/0.0002

Average speed = 10,000 m/s

Therefore, the average speed of the

electron is 10,000 meters per seconds.

Scientists create models to better understand Earth. Which evidence has led scientists to conclude that there are different layers within Earth's interior?

A.analysis of seismic wave data


B.measurement of Earth's diameter


C.temperatures taken within each layer


D.rock samples taken from Earth's core

Answers

Answer:

it is A or D

Explanation:

     

Answer:

ANswer:A

Explanation:

Allen and Jason are chucking a speaker around. On one particular throw, Allen throws the speaker, which is playing a pure tone of frequency f, at a speed of 10 m/s directly towards Jason, but his aim is a bit off. As a result, Jason runs forward towards the speaker at a speed of 6 m/s before catching it. Then, the frequency that Jason hears while running can be written as (m/n)f Hz, where m and n are relatively prime positive integers. Compute m n.

Answers

Answer:

Explanation:

We shall apply Doppler's effect of sound .

speaker is the source , Jason is the observer . Source is moving at 10 m /s , observer is moving at  6 m/s .

apparent frequency = [tex]f_o\times\frac{V+v_o}{ V-v_s}[/tex]

V is velocity of sound , v₀ is velocity of observer and v_s is velocity of source and f_o is real frequency of source .

Here V = 340 m/s , v₀ is 6 m/s , v_s is 10 m/s . f_o = f

apparent frequency =  [tex]f\times \frac{340+6}{340-10}[/tex]

= [tex]f\times \frac{346}{330}[/tex]

So m = 346 , n = 330 .

An inductor is connected to a 120-V, 60-Hz supply. The current in the circuit is 2.4 A. What is the inductive reactance

Answers

Answer:

Inductive reactance is 50.00 ohms

Explanation:

Given the following data;

Voltage = 120v

Frequency = 60Hz

Current = 2.4 A

To find the inductive reactance;

Inductive reactance, XL = V/I

Where;

XL represents the inductive reactance. V represents the voltage. I represents the current.

Substituting into the equation, we have;

XL = 120/2.4

XL = 50.00 ohms

If you travel from Tucson to Argentina, you will see some different constellations in the night sky. true or false

Answers

Answer:

its true!!

Explanation: have a nice day !!

In a particular crash test, an automobile of mass 1577 kg collides with a wall and bounces back off the wall. The x components of the initial and final speeds of the automobile are 17 m/s and 1.5 m/s, respectively. If the collision lasts for 0.18 s, find the magnitude of the impulse due to the collision. Answer in units of kg · m/s.

Answers

Answer:

Ft=24,443.5 kgm/s

Explanation:

Step one

Given data

Mass of automobile m=1577kg

Initial Velocity u=17m/s

Final Velocity v=1.5m/s

Time t=0.18s

Step two

From the impulse and momentum equation

Ft=mΔv

Substitute

Ft=1577*(17-1.5)

Ft=1577*15.5

Ft=24,443.5 kgm/s

A 22.0 kg child is riding a playground merry-go- round that is rotating at 40.0 rev/min. What centripetal force must

Answers

Answer:

F = 482.51 N

Explanation:

Given that,

Mass of a child, m = 22 kg

Angular velocity of the merry-go-round, [tex]\omega=40\ rev/min[/tex]

Let the radius of the path, r = 1.25 m

We need to find the centripetal force acting on the child. The formula for the centripetal force is given by :

[tex]F=m\omega^2r\\\\=22\times (4.18879)^2\times 1.25\\\\=482.51\ N[/tex]

So, the required centripetal force is 482.51 N.

2. A 2500 kg car is slowed down uniformly from an initial velocity of 20.0 m/s to
the north by a 6250 N braking force acting opposite the car's motion. Use the
impulse-momentum theorem to answer the following questions:
a. What is the car's velocity after 2.50 s?
b. How far does the car move during 2.50 s?
c. How long does it take the car to come to a complete stop?

Answers

Answer:

13.75m/s; 42.2m; 8s

Explanation:

(a) the car's velocity after 2.50 s is 13.75 m/s

(b) The distance traveled by the car is 42.18 m

(c)  the time taken for the car to come to complete stop is 8 s.

The given parameters;

mass of the car, m = 2500 kg

initial velocity of the car, u = 20 m/s

breaking applied on the car, f = 6250 N

The acceleration of the car is calculated as follows;

[tex]F = ma \\\\a = \frac{F}{m} = \frac{6250}{2500} = 2.5 \ m/s^2[/tex]

(a) Using impulse-momentum theorem, the car's velocity after 2.5 s is calculated as follows;

[tex]F = \frac{m(u-v)}{t} \\\\m(u-v) = Ft\\\\u-v = \frac{Ft}{m} \\\\v = u - \frac{Ft}{m} \\\\v = 20 - \frac{6250 \times 2.5}{2500} \\\\v = 13.75 \ m/s[/tex]

(b) The distance traveled by the car during the 2.5 s;

[tex]v^2 = u^2 - 2as\\\\2as = u^2 - v^2\\\\s = \frac{u^2 - v^2}{2a} \\\\s = \frac{20^2 - 13.75^2}{2\times 2.5} \\\\s = 42.18 \ m[/tex]

(c) The time taken for the car to come to a complete stop;

when the car stop's the final velocity, v = 0

v = u - at

0 = 20 - 2.5t

2.5t = 20

[tex]t = \frac{20}{2.5} \\\\t = 8 \ s[/tex]

Thus, the time taken for the car to come to complete stop is 8 s.

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