In figure shown, the graph shows the variation of a uni-directional force F acting on a body of mass 10 kg (in gravity free space), with time t. The velocity of the body at t = 0 is zero

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.
Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA
The power of the force at t = 12 s is
P = F.V.
The change in momentum of the body between the time t = 10 s to 15 s is
P = area of F-t curve from z = 10 + 0 + 0t = 5
The average acceleration of the body from t = 0 to t = 15 s is
No solution
The velocity of the body at t = 30 s is
v = 30 m/s