Answer:
(a) To calculate the velocity of the body, we can use the equation:
force = mass x acceleration
where acceleration = change in velocity / time
Rearranging the equation, we get:
acceleration = force / mass
acceleration = 10N / 2kg
acceleration = 5 m/s^2
Now, we can use the equation:
velocity = initial velocity + acceleration x time
Since the body was at rest initially, the initial velocity is 0. Therefore:
velocity = 0 + 5 m/s^2 x 3 s
velocity = 15 m/s
(b) The change in momentum of the body can be calculated using the equation:
change in momentum = final momentum - initial momentum
Since the body was at rest initially, the initial momentum is 0. Therefore:
final momentum = mass x velocity
final momentum = 2 kg x 15 m/s
final momentum = 30 kg m/s
change in momentum = 30 kg m/s - 0
change in momentum = 30 kg m/s
(c) The rate of change of momentum in the body is simply the change in momentum divided by the time taken. Therefore:
rate of change of momentum = change in momentum / time
rate of change of momentum = 30 kg m/s / 3 s
rate of change of momentum = 10 kg m/s^2
So the rate of change of momentum in the body is 10 kg m/s^2.