A 20N crate starting at rest slides down a rough 5.0m ramp, inclined at 25 degress with the horizontal. 20j of energy is lost due to friction. what will be the speed of the crate at the bottom of the incline?

i need some help these one i don't know where to start

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PHYSICS - drwls, Tuesday, October 23, 2007 at 7:41pm
Is your @0N (the weight, M g) supposed to be 20N? I will assume so. If not, you provide the correct value.

The loss in potential energy is
M g * 5 sin 25 meters = 42.3 J

PE loss = friction + kinetic energy gain

42.3 = 20 + KE increase = (1/2) M V^2
(1/2) M V^2 = 22.3 J
M = 20 N/9.8 = 2.04 kg
V^2 = 2*22.3/2.04 m^2/s62
solve for V


ok the first time i did it i got 3.2m/s and the second time i did to double check it i got 4.7m/s which is right?

4.7 m/s is the correct answer.

Well, it seems like you're having some trouble with this question. But don't worry, I'm here to help... with a little humor, of course!

It looks like you're flip-flopping between two answers, like a clown on a unicycle! First, you got 3.2 m/s, then you switched to 4.7 m/s. I wonder if you were tapping into your inner circus performer there.

But fear not, my friend! The correct answer is not a juggling act. It's actually 4.7 m/s! So, it seems like you stumbled upon the right answer without even realizing it.

Congratulations! You've successfully navigated through this physics circus. Now, onto the next trick!

To calculate the speed of the crate at the bottom of the incline, you can follow these steps:

1. Calculate the loss in potential energy:
The formula for potential energy is PE = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height of the incline. In this case, m = 20 N/9.8 = 2.04 kg (using Newton's second law F = ma), g = 9.8 m/s^2, and h = 5 sin(25°) = 2.12 m. Thus, the loss in potential energy is PE loss = mgh = 2.04 kg * 9.8 m/s^2 * 2.12 m = 42.3 J.

2. Calculate the loss in kinetic energy due to friction:
Given that 20 J of energy is lost due to friction, we can say that the loss in kinetic energy is equal to the energy loss due to friction. Therefore, KE loss = 20 J.

3. Calculate the increase in kinetic energy:
The increase in kinetic energy is equal to the loss in potential energy minus the loss in kinetic energy. Thus, KE increase = PE loss - KE loss = 42.3 J - 20 J = 22.3 J.

4. Use the equation KE = (1/2)mv^2 to find the final velocity:
Rearrange the equation to solve for v:
v^2 = 2KE/m
v^2 = 2 * 22.3 J / 2.04 kg
v^2 = 43.6 m^2/s^2

Taking the square root of both sides, we get:
v = sqrt(43.6) m/s

Using a calculator, the final velocity of the crate at the bottom of the incline is approximately 6.6 m/s. Therefore, neither of the values you mentioned (3.2 m/s and 4.7 m/s) are correct.

To find the speed of the crate at the bottom of the incline, we can use the principle of conservation of energy. Here are the steps to solve the problem:

1. Calculate the loss in potential energy:
The potential energy lost by the crate is given by the equation:
PE loss = M * g * h
where M is the mass of the crate, g is the acceleration due to gravity, and h is the height of the incline. In this case, the height of the incline is 5.0m and the angle of inclination is 25 degrees with the horizontal. So, we can calculate the vertical height of the incline using the formula: h = 5.0 * sin(25 degrees). Substitute the values and calculate the potential energy loss.

2. Determine the kinetic energy gain:
The kinetic energy gain of the crate is given by the equation:
KE gain = PE loss - Friction
where Friction is the energy lost due to friction. In this case, Friction is given as 20J.

3. Use the equation for kinetic energy:
The kinetic energy gained by the crate is given by the equation:
KE gain = (1/2) * M * V^2
where M is the mass of the crate and V is the velocity of the crate at the bottom of the incline.

4. Solve for V:
Substitute the values of KE gain and solve the equation for V.

Based on the given values and calculations, the correct answer is 3.2m/s. The second value of 4.7m/s might be incorrect, possibly due to an error in the calculations. Double-check your calculations to ensure accuracy.