# ImpulseWatch

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#1

A club head is in contact with the ball for a time of 222 microseconds. The club head has mass 0.17 kg and the ball has mass 0.045 kg. At the moment of contact, the ball is at rest and the club head is moving with a speed of 38 m s-1. The ball moves off with an initial speed of of 63 m s-1.

a) Calculate the average force acting on the ball while the club head is in contact with the ball.

b) State the average force acting on the club head while it is in contact with the ball.

c) Calculate the speed of the club head at the instant that it loses contact with the ball.

220 microseconds = 2.2 X 10-4 seconds

Impulse = FΔt = mΔv

A:

F =(mΔv)/Δt

Δv = 63 - 38 = 25 m s-1
Δt = 220 x 10-4 s

I don't understand what to use for m. Do I add the two masses together or do I just use one?

B:

Ditto

C:

I think I work out the momentum using p=mv and then E=1/2mv2?
0
4 years ago
#2
A. Mass of the ball if you are using the change in velocity of the ball.
C. Conservation of momentum.
Momentum of ball and club before = momentum of ball and club after
You know all values of m, and of velocities before and after except for the final velocity of the club.
0
#3
(Original post by Stonebridge)
A. Mass of the ball if you are using the change in velocity of the ball.
C. Conservation of momentum.
Momentum of ball and club before = momentum of ball and club after
You know all values of m, and of velocities before and after except for the final velocity of the club.
A: I did (0.045 X 26) / (220 X 10^-4) and got 5.1 X 10^-7 N. It isn't right... The answer on the mark scheme is 1.3 X 10^4 N.

B: would it just be negative A then?

Thank you so much
0
4 years ago
#4
(Original post by ILovePancakes)
A: I did (0.045 X 26) / (220 X 10^-4) and got 5.1 X 10^-7 N. It isn't right... The answer on the mark scheme is 1.3 X 10^4 N.

B: would it just be negative A then?

Thank you so much
Where does the 26 come from?

The ball is initially at rest and its velocity after impact is 63 m/s
0
#5
(Original post by Stonebridge)
Where does the 26 come from?

The ball is initially at rest and its velocity after impact is 63 m/s
Oh my gosh it's the ball!!! I was doing the velocity of the club.

Thank you!!
0
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