CHAPTER 12. FORCE,MOMENTUM AND IMPULSE 12.6
(a) Calculate the speedat which the ball strikesthe glass plate.
(b) Show that the speedof the ball immediately after breaking the plate is2,0 m·s−^1.
(c) Calculate the magnitude and give the direction of the change ofmomentum
which the ball experiences during its contact with the glass plate.
(d) Give the magnitudeand direction of the impulse which the glass plate experi-
ences when the ball hitsit.
- [SC 2004/11 HG1]Acricket ball, mass 175 gis thrown directly towards a player at
a velocity of 12 m·s−^1. It is hit back in the opposite direction with a velocity of 30
m·s−^1. The ball is in contact with the bat for a period of 0,05 s.
(a) Calculate the impulse of the ball.
(b) Calculate the magnitude of the force exertedby the bat on the ball.
- [IEB 2005/11 HG1]A ball bounces to a vertical height of 0,9 m when it is dropped
from a height of 1,8 m.It rebounds immediatelyafter it strikes the ground, and the
effects of air resistance are negligible.
1,8 m
0,9 m
(a) How long (in s) does it take for the ball to hit the ground afterit has been
dropped?
(b) At what speed doesthe ball strike the ground?
(c) At what speed doesthe ball rebound from the ground?
(d) How long (in s) doesthe ball take to reach itsmaximum height after the bounce?
(e) Draw a velocity-timegraph for the motion ofthe ball from the time itis dropped
to the time when it rebounds to 0,9 m. Clearly, show the following on the graph:
i. the time when the ball hits the ground
ii. the time when it reaches 0,9 m
iii. the velocity of the ball when it hits the ground, and
iv. the velocity of the ball when it rebounds fromthe ground.
- [SC 2002/11 HG1]In a railway shunting yard, a locomotive of mass 4 000 kg, trav-
elling due east at a velocity of 1,5 m·s−^1 , collides with a stationary goods wagon of
mass 3 000 kg in an attempt to couple with it. The coupling fails and instead the
goods wagon moves due east with a velocity of2,8 m·s−^1.
(a) Calculate the magnitude and direction of the velocity of the locomotive imme-
diately after collision.
(b) Name and state in words the law you used toanswer question (18a)
- [SC 2005/11 SG1] Acombination of trolley A(fitted with a spring) of mass 1 kg, and
trolley B of mass 2 kg, moves to the right at 3 m·s−^1 along a frictionless, horizontal
surface. The spring is kept compressed betweenthe two trolleys.
A
1 kg
B
2 kg
3 m·s−^1
Before
