<h2>
a) Change in momentum is 4000 kg m/s in the direction of motion</h2><h2>
b) Magnitude of the force is 80 N</h2>
Explanation:
Force is given by rate of change of momentum.
Mass of object = 200 kg
Initial velocity = 5 m/s
Final velocity = 25 m/s
a) Change in momentum = 200 x 25 - 200 x 5
Change in momentum = 4000 kg m/s in the direction of motion
b) Time taken = 50 s
Rate of change of momentum = Change in momentum ÷ Time
Rate of change of momentum = 4000 ÷ 50
Rate of change of momentum = 80 N
Force = 80 N
Magnitude of the force is 80 N