Question

A body of mass 10kg is raised to height 10 m from rest
state by applying a force 120 N in vertically upward
direction. Find its final kinetic energy and mechanical
energy. Taking zero of gravitational potential energy on
the earth's surface and g=10 m/s2.​

Answer 1

Answer:

Work against the gravity will be PE=mgh=5×10×10=500J

Total work done by the external force is W=Fd=170×10=1700J

so the kinetic energy gain will be KE=W−PE=1700J−500J=1200J

if the velocity becomes v then

2

1

mv

2

=1200Joule

or velocity v=

5

2400

=21.9m/s