by how much does the momentum of a body of mass 54kg change when its speed

1.decreases from 20m/s to 0.20m/s ;and
2.increases from 30m/s to 40m/s

To find the change in momentum of a body, we can use the equation:

Change in momentum = Final momentum - Initial momentum

The momentum of an object is calculated by multiplying its mass by its velocity (speed). So, the initial momentum can be calculated as mass times initial velocity, and the final momentum can be calculated as mass times final velocity.

Let's calculate the change in momentum for each case:

1. Decrease in speed from 20 m/s to 0.20 m/s:
Initial momentum = mass x initial velocity
= 54 kg x 20 m/s
= 1080 kg*m/s

Final momentum = mass x final velocity
= 54 kg x 0.20 m/s
= 10.8 kg*m/s

Change in momentum = Final momentum - Initial momentum
= 10.8 kg*m/s - 1080 kg*m/s
= -1069.2 kg*m/s (negative value indicates a decrease in momentum)

2. Increase in speed from 30 m/s to 40 m/s:
Initial momentum = mass x initial velocity
= 54 kg x 30 m/s
= 1620 kg*m/s

Final momentum = mass x final velocity
= 54 kg x 40 m/s
= 2160 kg*m/s

Change in momentum = Final momentum - Initial momentum
= 2160 kg*m/s - 1620 kg*m/s
= 540 kg*m/s

Therefore, the change in momentum is -1069.2 kg*m/s when the speed decreases from 20 m/s to 0.20 m/s, and the change in momentum is 540 kg*m/s when the speed increases from 30 m/s to 40 m/s.