Question

Please help me out. :(

A box slides down a smooth inclined plane 30 m long and 10 m high. Find its speed at the bottom of the plane if it starts from rest at the top. Compare this with the speed gained by a body in falling freely from rest through 10m.

Answer 1

is it 30 m long on diagonal or 30 m long horizontally ?

Answer 2

diagonal maybe?

Answer 3

Use law of conservation of energy to the point where the box is starting to move and to the point at bottom of the inclined plane.

Take the reference level at the bottom of the plane as well.

At the top of the plane where the box starts to move the total energy is only with the potential energy - \(mgh\)

At the bottom the box contains only the kinetic energy as the total energy - \(\frac 12 mv^2\).

since the total energy of the two points are the same equate two expressions and get the velocity