Analyze the problem of known:<br><br> Unknown:

The magnitude of the force of the bottom block on the top block is _____ the magnitude of the force of the earth on the top bloc

ra1l [238]

Hello. This question is incomplete. The full question is:

Two blocks are stacked on top of each other on the floor of an elevator. For each of the following situations, select the correct relationship between the magnitudes of the two forces given.

The elevator is moving downward at a constant speed.

The magnitude of the force of the bottom block on the top block is _____ the magnitude of the force of the earth on the top block.

Answer:

The magnitude of the force of the bottom block on top block is equal to the magnitude of the force of the top block on bottom block.

Explanation:

As the elevator is descending, there is only a normal force being applied to the lower surface of the block. This force has a magnitude equal to the force of the upper block, because the only acceleration that is acting in this case is the force of gravity. From that force, the resulting force is zero.

6 0

3 years ago

What is the mass of a 5000 N car on Earth?

puteri [66]

Answer:

510.2kg

Explanation:

use w=mg then put the value you will get answer

4 0

3 years ago

A pendulum consists of a 2.0 kg stone swinging on a4.0 m string of negligible mass. The stone has a speed of 8.0 m/swhen it pass

arlik [135]

Answer:

a) $v_{60^{o}} =4.98 m/s$

b) $\theta_{max}=79.34^{o}$

Explanation:

This problem can be solved by doing an energy analysis on the given situation. So the very first thing we can do in order to solve this is to draw a diagram of the situation. (see attached picture)

So, in an energy analysis, basically you will always have the same amount of energy in any position of the pendulum. (This is in ideal conditions) So in this case:

$K_{lowest}+U_{lowest}=K_{60^{o}}+U_{60^{0}}$

where K is the kinetic energy and U is the potential energy.

We know the potential energy at the lowest of its trajectory will be zero because it will have a relative height of zero. So the equation simplifies to:

$K_{lowest}=K_{60^{o}}+U_{60^{0}}$

So now, we can substitute the respective equations for kinetic and potential energy so we get:

$\frac{1}{2}mv_{lowest}^{2}=\frac{1}{2}mv_{60^{o}}^{2}+mgh_{60^{o}}$

we can divide both sides of the equation into the mass of the pendulum so we get:

$\frac{1}{2}v_{lowest}^{2}=\frac{1}{2}v_{60^{o}}^{2}+gh_{60^{o}}$

and we can multiply both sides of the equation by 2 to get:

$v_{lowest}^{2}=v_{60^{o}}^{2}+2gh_{60^{o}}$

so we can solve this for $v_{60^{o}}$ . So we get:

$v_{60^{o}}=\sqrt{v_{lowest}^{2}-2gh_{60^{0}}}$

so we just need to find the height of the stone when the pendulum is at a 60 degree angle from the vertical. We can do this with the cos function. First, we find the vertical distance from the axis of the pendulum to the height of the stone when the angle is 60°. We will call this distance y. So:

$cos \theta = \frac{y}{4m}$

so we solve for y to get:

$y = 4cos \theta$

so we substitute the angle to get:

y=4cos 60°

y=2 m

so now we can find the height of the stone when the angle is 60°

$h_{60^{o}}=4m-2m$

$h_{60^{o}}=2m$

So now we can substitute the data in the velocity equation we got before:

$v_{60^{o}}=\sqrt{v_{lowest}^{2}-2gh_{60^{0}}}$

$v_{60^{o}} = \sqrt{(8 m/s)^{2}-2(9.81 m/s^{2})(2m)}$

so

$v_{60^{o}}=4.98 m/s$

b) For part b, we can do an energy analysis again to figure out what the height of the stone is at its maximum height, so we get.

$K_{lowest}+U_{lowest}=K_{max}+U_{max}$

In this case, we know that $U_{lowest}$ will be zero and $K_{max}$ will be zero as well since at the maximum point, the velocity will be zero.

So this simplifies our equation.

$K_{lowest} =U_{max}$

And now we substitute for the respective kinetic energy and potential energy equations.

$\frac{1}{2}mv_{lowest}^{2}=mgh_{max}$

again, we can divide both sides of the equation into the mass, so we get:

$\frac{1}{2}v_{lowest}^{2}=gh_{max}$

and solve for the height:

$h_{max}=\frac{v_{lowest}^{2}}{2g}$

and substitute:

$h_{max}=\frac{(8m/s)^{2}}{2(9.81 m/s^{2})}$

to get:

$h_{max}=3.26m$

This way we can find the distance between the axis and the maximum height to determine the angle of the pendulum about the vertical.

y=4-3.26 = 0.74m

next, we can use the cos function to find the max angle with the vertical.

$cos \theta_{max}= \frac{0.74}{4}$

$\theta_{max}=cos^{-1}(\frac{0.74}{4})$

so we get:

$\theta_{max}=79.34^{o}$

5 0

3 years ago

You are not allowed to park within

aleksandr82 [10.1K]

Answer:

The correct answer is - 30 feet.

Explanation:

According to the parking laws one should not park within 30 feet of any flashing signal, stop sign, or traffic signal it is not allowed. Parking is also not allowed in case of the following situations -

On crosswalks

In front of driveways

double parking

On sidewalks.

at "No Parking" signs are posted.

Within intersections or 20 feet of an intersection.

Within 15 feet of a fire hydrant.

8 0

3 years ago

Read 2 more answers

A 6.25 L tank holds helium gas at a pressure of 1759 psi. A second 6.25 L tank holds oxygen at a pressure of 467.7 psi. The two

rodikova [14]

Answer:

P=1113.35 psi

Explanation:

For tank 1

V₁= 6.25 L

P₁=1759 psi

For tank 2

V₂=6.25 L

P₂=467.7 psi

Lets take final pressure is P

The final volume V= 6.25 + 6.25 L = 12.5 L

P V = V₂P₂+V₁P₁

Now by putting the values

P V = V₂P₂+V₁P₁

P x 12.5 = 6.25 x 467.7+6.25 x 1759

P=1113.35 psi

So the final volume of the system will be 1113.35 psi.

8 0

3 years ago

Analyze the problem of known: Unknown: