Question

A 288-gram cart starts from rest and rolls down an inclined plane from a height of 1.226 m. Determine its speed (in m/s) at a height of 0.126 m above the bottom of the incline. Assume friction is negligible

Answer 1

The law of conservation energy

PE₁ + KE₁ = PE₂ + KE₂

From rest ⇒ v₁ = 0 ⇒ KE₁ = 0

Input the value:

PE₁ = PE₂ + KE₂

`\tt mgh_1=mgh_2+(1)/(2)mv_2^2\rightarrow divide\:m\\\\gh_1=gh_2+(1)/(2)v_2^2\\\\9.8(1.226-0.126)=(1)/(2)v_2^2\\\\v_2=4.64\:m/s`