Frictionless inclined plane physics homework

It should be F = (2 kg)(9.8 m/s^2)(sin30) = 4.9 NIn summary, a 2.0 kg mass slides down a frictionless inclined plane at a 30 degree angle with the horizontal. Starting from rest, the mass reaches a speed of 1.21 m/s after sliding 3.0 m along the incline. The correct method for calculating the force is using F = M g sin (theta).
  • #1
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A 2.0 kg mass slides down a frictionless inclined plane that makes an angle of 30 degrees with the horizontal. The sass starts from rest. What is its speed after it has slid a distance of 3.0 m along the incline?

I got:

F = (sin30)(9.8)
F = 4.9 N

W = Fd
W = (4.9) (3) = 14.7 J

W = E_kin
14.7 J = 1/2 mv^2
v = 1.21 m/s

Is my method correct? I'm very unsure how to do this one. Thanks.
 
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  • #2
your Work-Energy method is excellent ...
but a few chapters ago, F = M g sin (theta)
. . . if you had USED units [kg N/kg] you would have caught your error.
 
  • #3
F = M g sin (theta) ?

I'm not sure what you mean. :confused:
 
  • #4
you forgot the mass when you calculated the force.
 

Related to Frictionless inclined plane physics homework

1. What is an inclined plane?

An inclined plane is a simple machine that consists of a flat surface that is raised at one end. It is commonly used to reduce the amount of force needed to move an object up or down a slope.

2. How does friction affect an object on an inclined plane?

Friction is the force that resists the motion of an object. On an inclined plane, friction acts in the opposite direction of the object's motion, making it harder for the object to move. The steeper the incline, the more friction there will be.

3. What is the formula for calculating the force of gravity on an object on an inclined plane?

The formula for calculating the force of gravity on an object on an inclined plane is F = mg sinθ, where F is the force of gravity, m is the mass of the object, g is the acceleration due to gravity (9.8 m/s²), and θ is the angle of the incline.

4. How does the angle of the incline affect the force needed to move an object?

The angle of the incline directly affects the force needed to move an object. As the incline becomes steeper, the force needed to move the object increases. This is because the component of the force of gravity acting parallel to the incline also increases.

5. What is the advantage of using an inclined plane?

The advantage of using an inclined plane is that it reduces the amount of force needed to move an object up or down a slope. This makes it easier and more efficient to move heavy objects, as less force is required compared to lifting them straight up or down.

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