Question

A body of mass 20kg is moving along straight line with a linear momentum of 240kgm/s.If a constant force of 20N acts for 5 seconds opposite to the direction of motion, the work done by the force during this time is?​

Answer 1

Answer:

1200J

Explanation:

given:-

Mass (m) = 20kg

Momentum (p) = 240kgm/s

Force (F) = 20N

Time (t) = 5sec

Work (W) = ?

We know,

p=mv (where v is velocity)

v=p/m = 240/20 = 12m/s

also,

s = v×t (where s is displacement)

s = 12×5 = 60m

Now,

W = F×s

W = 20×60

W = 1200J