Answer :
The velocity at the bottom : v = 8.85 m/s
Further explanation
Given
height of the hill = 4 m
Required
The velocity at the bottom
Solution
The law of conservation energy :
ME₁=ME₂
(PE+KE)₁ = (PE+KE)₂
initially at rest⇒vo=0⇒KE₁=0
At the bottom⇒h=0⇒PE₂=0
So the equation becomes :
PE₁=KE₂
mgh=1/2.mv²
gh = 1/2v²
[tex]\tt v=\sqrt{2gh}[/tex]
v = √2x9.8x4
v = 8.85 m/s