Question

JVIAI
A man lifts slowly a suitcase weighing 2 kg from the platform and puts it on his head 2.0 m above the platform. Find
the work done by the man on the suitcase in joules (Take g = 10 m/s2)​

Answer 1

Given info : A man lifts slowly a suitcase weighing 2 kg from the platform and puts it on his head 2.0 m above the platform.

To find : the work done by the man on the suitcase in joules.

Solution : applying work - energy theorem,

Workdone by the man + workdone by the gravity = change in kinetic energy

⇒work done by the man + work done by the gravity = 0

⇒work done by the man = - work done by the gravity = -mgh

Here, m = 2kg, g = 10 m/s² and h = 2m

So, workdone by the man = -2 × 10 × 2 = -40 J

Therefore workdone by the man on the suitcase in joules is -40 J