A body of mass 25 kg is moving with a velocity of 30 m/s. A force of 50N is applied on it for 5 seconds which changes its velocity to v m/s. the final velocity is
a) 40m/s b) 50m/s c) 20m/s d) 45m/s
Answers
Answer:
Answer:
Rate of change of momentum = 50 N
Acceleration of the body = 2\ m/s^22 m/s2
Force on the body = 50 N
Explanation:
Given:
m = mass of the body = 25 kg
u = initial velocity of the body = 30 m/s
v = final velocity of the body = 40 m/s
t = time interval = 5 s
Assume:
a = acceleration of the body
F = force of on the body
\Delta PΔP = change in momentum of the body
Rate of change in momentum = \dfrac{\Delta P}{t}=\dfrac{m(v-u)}{t}=\dfrac{25(40-30)}{5} = 50\ NtΔP=tm(v−u)=525(40−30)=50 N
According to the Newton's second law, the rate of change of momentum is the force applied on the body.
\begin{gathered}\therefore F = \dfrac{\Delta P}{t}=50\ N\\\end{gathered}∴F=tΔP=50 N
Force on the body = 50 N
Acceleration of the body = \dfrac{F}{m}=\dfrac{50}{25} = 2\ m/s^2mF=2550=2 m/s2