# Crate pushed up an inclined plane

• rrosa522
In summary, the conversation discusses a warehouse worker pushing a 24 kg crate up a ramp with no friction. The component of gravitational force along the ramp's surface is calculated to be 120N, and the force required to move the crate at a constant speed is also calculated. The total work done in pushing the crate 23 m along the ramp is also determined, assuming constant velocity. Lastly, the coefficient of kinetic friction between the crate and ramp is taken into account to calculate the work done by the worker and by friction, as well as the total work done as the worker pushes the crate 16 m up the ramp.
rrosa522

## Homework Statement

A warehouse worker pushes a crate of mass 24 kg up a ramp. Assume that the friction between the crate and ramp can be ignored.
a) Determine the component of gravitational force directed along the ramp's surface.
b) Calculate the force required to move the crate at a constant speed up the ramp.
c) Calculate the work done in pushing the crate 23 m as measured along the ramp. Assume the crate moves at a constant velocity.
d) Assume the coefficient of kinetic friction between the crate and the ramp is μk = 0.25. Calculate the work done on the crate by the worker and by friction, and calculate the total work done as the worker pushes the crate 16 m up the ramp.

## The Attempt at a Solution

for (a) I got 235N (just multiplied mass by 9.81) but the answer is 120N

rrosa522 said:
I got 235N (just multiplied mass by 9.81)
That would be the crate's weight. But they are asking for a component of the weight. (What angle does the ramp make with the horizontal?)

Doc Al said:
That would be the crate's weight. But they are asking for a component of the weight. (What angle does the ramp make with the horizontal?)
30 degrees

rrosa522 said:
30 degrees
OK. Now draw yourself a diagram. Use it and a little trig to find the components of the weight parallel and perpendicular to the incline.

And if you do that:
fgx=fgcos30
=(24)(9.8)cos30
=203.69N

but it says the correct answer is 120N, am I doing something wrong, this seems pretty basic but idk.

ava ray said:
And if you do that:
fgx=fgcos30
=(24)(9.8)cos30
=203.69N

but it says the correct answer is 120N, am I doing something wrong, this seems pretty basic but idk.
You found the component of the weight perpendicular to the plane, but they want the component parallel to it.

whoops I have to use sin
just noticed thanks

## 1. What is an inclined plane?

An inclined plane is a simple machine that is a flat surface set at an angle or incline. It is used to help move objects from a lower level to a higher level with less force.

## 2. How does a crate move up an inclined plane?

A crate can move up an inclined plane due to the force of gravity. When the crate is placed on the incline, gravity pulls it downwards. However, the incline acts as a ramp, allowing the crate to move up with less force needed.

## 3. What factors affect the movement of a crate up an inclined plane?

The factors that affect the movement of a crate up an inclined plane include the angle of the incline, the weight of the crate, and the force applied to move the crate.

## 4. Does the height of the inclined plane affect the movement of the crate?

Yes, the height of the inclined plane does affect the movement of the crate. The higher the incline, the greater the force needed to move the crate up the incline.

## 5. Can an inclined plane be used to move objects horizontally?

Yes, an inclined plane can be used to move objects horizontally. This is known as a ramp and is commonly used to move heavy objects such as furniture or vehicles.

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