A body of mass is initially moving with speed at a height above the ground

PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power

Problem

A body of mass

m

is initially moving with speed

u

at a height

h_{0}

above the ground. It later reaches a point at height

h

above the ground with speed

v

. Air resistance is negligible. (i) Write expressions for the total mechanical energy of the body at the initial and the final positions in terms of

m

u

v

g

h_{0}

and

h

. (ii) Equate the two expressions obtained in part (i) and simplify to derive the relation

v^{2}=u^{2}+2g(h_{0}-h)

. (iii) State any two practical situations where this relation is useful in solving problems of motion under gravity.