Question

Velocity of an object of mass 5kg increases from 3m/s to 7m/s on applying a force continuously for 2s.Find out the force applied if the duration for which force acted is extended to 5s.What will be the velocity of the object then?
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Answer 1

Explanation:

u=3 m/s

v=7 m/s

t=2s

m=5 kg

According to Second Law of Motion F=ma

=

t

m(v−u)

=

2

5(7−3)

=10 N

Acceleration a=

m

F

=

5

10

=2m/s

2

If we substitute the values in the equation v=u+at velocity can be calculated when the time for force is extended to 5s

v=3+(2×5)=12 m/s