Question

The velocity of a body of mass 10 kg increases from 10 m/s to 50 m/s in 5 second .The force acting on the body is
15 N
80 N
50 N
10 N​

Answer 1

Answer:

Mass of the body =10 kg

Initial velocity u=4 m/s

Final velocity v=8 m/s

Time t=2s

a) Momentum before force acts p

1

​

=m×u=10×4=40kg.m/s

b) Momentum after force acts p

2

​

=m×v=10×8=80kg.m/s

c) Gain in momentum per second =

2

40

​

=20kg.m/s

d) Acceleration a=

t

v−u

​

=

2

8−4

​

=2m/s

2

Force =m×a=10×2=20 N

Explanation:

Answer 2

Mass of the body =10 kg
Initial velocity u=4 m/s
Final velocity v=8 m/s
Time t=2s
a) Momentum before force acts p
1
​
=m×u=10×4=40kg.m/s
b) Momentum after force acts p
2
​
=m×v=10×8=80kg.m/s
c) Gain in momentum per second =
2
40
​
=20kg.m/s
d) Acceleration a=
t
v−u
​
=
2
8−4
​
=2m/s
2

Force =m×a=10×2=20 N