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
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]