Question

an object of mass 10 kg is dropped from a height of 100cM find its kinetic energy and velocity just as it reaches the ground

Answer 1

Potential Energy (P. E.) = mgh
=10Kg*10m/s^2 * 1 metre(since 100cm=1m)
=10*10*1
=100 Joules
PE = KE (Because of the law of conservation of energy.)
100J = 1/2 * m * v^2
100J = 0.5*10*v^2
100J = 5*v^2
100J ÷ 5 = V^2
20 = V^2
V =
$\sqrt{20}$
= 4.472 m/s
= 4.5 m/s (approx.)
Therefore, the Kinetic Energy is 100 Joules and the Velocity is 4.45 m/s (approximately).
Hope this helps