IMPULSE AND IMPULSIVE FORCE

A softball player moves his hand backward while catching a fast-moving ball. This movement of the hand is to

• Increase the impulsive force

• Increase the stopping time of the ball

• Control the ball to stop it from falling

The diagram shows an athlete performing the high jump. What is the function of the mattress?

• To reduce the collision time between the athlete and the mattress

• To reduce the change of momentum of the athlete when he hits the mattress

• To reduce the impulsive force acting on the athlete when he hits the mattress

Diagram 2 shows a parachutist landing with his legs bent. Why does the parachutist bend his legs?

• To lengthen the time of impact of his feet with the ground

• To shorten the time of impact of his feet with the ground

• To lengthen the time of falling to the ground

Diagram 5 shows a box with a mass of 55 kg is dropped from a helicopter. At the moment before touching the ground, the velocity of the box is 12 ms ^-1. The box stops 2 seconds after touching the ground. What is the magnitude of the impulsive force acted on the box?

• 660 N

• 330 N

• 122 N

• 110 N

Diagram 2 shows an athlete bending his legs upon landing in a long jump event. The athlete bent his legs to reduce the

• impulse on his feet

• impulsive force on his feet

• velocity just before landing

• time of impact between his feet and the sand

Diagram 1 shows two identical eggs are dropped from the same height, h, onto a floor and a sponge respectively. Which inference is correct?

• The impulsive force depends on the velocity of the egg

• The impulsive force depends on the time of impact

• The impulsive force depends on gravitational force

• The impulsive force depends on the height of the egg

Diagram 4 shows a martial art student breaking a pile of bricks. What is the physics concept that makes the brick break?

• Impulsive force

• Momentum

• Pressure

• Impulse

Diagram 2 shows a golfer hitting a golf ball. Impulsive force is produced when

• the golf club is swung at high velocity

• the golf club is swung backward

• the golf club hits the golf ball

• the golf ball moves in the air

An athlete of mass 50kg falling on a mattress in a high jump competition. He hits the mattress at a velocity of 10 ms^-1 and stops after 0.5 s.

• 1000 N

• 250 N

• 2.5 N

• 0 N

Diagram 6 shows a landing area for a long jump event. The sand is flattened after a long-jump is performed. Sand is used to reduce

• impulse

• momentum

• impulsive force

• effect of inertia