Question 1

A 0.50 kg football is thrown with a velocity of 15 m/s to the right. A stationary receiver catches the ball and brings it to rest in 0.020s . What is the force exerted on the receiver?

So I used mvf-mvi/change(t)

I got 375 for that one...

Question 2

A 0.40 kg soccer ball approaches a player horizontally with a velocity of 18 m/s to the north. The player strikes the ball and causes it to move in the opposite direction with a velocity of 22 m/s. What impulse was delivered to the ball by the player?

I am not sure on this one but I used the formula of: mass * change in velocity and got 1.6 N

Now the last I do not understand and if someone could help me I would really appreciate it:

Question 3

An 82 kg man drops from rest on a diving board 3.0 m above the surface of the water and comes to rest 0.55 after reaching the water. What force does the water exert on him?

I think I may be overthinking this (if that's a word hah) but does gravity play a part here with the 9.8 m/s 2 ?

Please help this assignment is very important to me.

1 answer

Question 1 is ok but you need to include the force units (Newtons)

In Question 2 you are asked for impulse, not the force. The impulse is 16 Newton-seconds. You missed a decimal point somewhere.

Yes, gravity plays a role in Question 3

Calculte his velocity when he hits the water; sqrt(2gH)= 7.67 m/s

Water exerts a force that (after subtracting the weight)cancels his momentum.

(F - Mg)*0.55 s = M*7.67 m/s)

F = M [g + (7.67 m/s)/0.55 s]