Question

A 5 kg mass is raised by a distance of 4 m by a vertical force of 80 N. If the mass was initially at rest, its final kinetic energy is :-​

Answer 1

Explanation:

Acceleration of boy upwards due to 80N force=

5kg

80N

=16m/s

2

Thus net acceleration upwards=16m/s

2

−10m/s

2

=6m/s

2

v

2

−u

2

=2as

⟹v

2

=2×6×4m

2

/s

2

=48m

/

s

2

Thus total kinetic energy=

2

1

mv

2

=120J