Impulse/change in momentum Level 2 Physics NCEA

Impulse is a change in momentum. Identify the equation(s) that you can use to calculate this value.

• Change in p = ma

• Change in p = F x t

• Change in p = p_(final)- p_(initial)

• Change in p = F / A

Mrs Glaister is hitting a punch bag with 450 kg ms^-1 momentum that comes to a standstill over 1.2 s. How much force is acting on her hand?

• 35 N^-1

• 70 N

• 150 N

• 375 N

Daisy and car has a momentum of 2500 kgms^-1 until a lamp post jumps out into the road making her stop rather quickly! What is her change in momentum?

• 0 kgms^-1

• 2500 kgms^-1

• 5000 kgms^-1

• 0.500 kgms^-1

Daisy and car has a momentum of 2500 kgms^-1 until a lamp post jumps out into the road making her stop rather quickly over 0.5 seconds. How much force was needed to do this?

• 200 N

• 1250 N

• 5000 N

• 0.500 N

Justice's hand 7.3 kg is moving at 3.5 ms^-1 before he hits the bag and is not moving. What is his change in momentum (impulse)?.

• 0 kgms^-1

• 12.25 kgms^-1

• 19.01 kgms^-1

• 25.55 kgms^-1

If the boxer was hitting the bag as hard as they could, what would be the result of doing the same thing but without a boxing glove on?

• No broken bones - as the change in momentum (impulse) is the smaller, but the glove increases the time the force that changes the momentum occurs over. This reduces the force acting to stop the hand and acting on the bones. .

• Broken bones - as the change in momentum (impulse) is the same, but without a glove the time the force acts over is smaller. This increases the force acting to stop the hand and its bones.

• Broken bones as the change in momentum (impulse) is the same, but the glove increases the time the force that changes the momentum occurs over. This reduces the force acting to stop the hand and acting on the bones. ^.

• Broken bones as the change in momentum (impulse) is the bigger, but the glove increases the time the force that changes the momentum occurs over. This increases the force acting to stop the hand and acting on the bones. .

James hits a punch bag and his 7.2 kg hand decelerates over a 0.55 s period. This occurs over 0.25s. What is his change in momentum/impulse?

• 0.32 kg ms^-1

• 0.55 kg ms^-1

• 0.72 kg ms^-1

• 0.99 kg ms^-1

Dave (80 kg) has just dived head first into the ball pit. He finished in this position after decelerating at 0.25 ms^-2. This happened over 1.5 seconds. Calculate the impulse.

• 0.3 kgms^-1

• 7 kgms^-1

• 30 kgms^-1

• 23 kgms^-1

Dave (80 kg) has just dived head first into the ball pit with a momentum of 1500 kgms^-1. The balls create a 200 N Force that does this. How long does it take Dave to stop?

• 2.5 s

• 7.5 s

• 1.0 s

• 1.45 s

A cycle helmet reduces the force of impact acting on the brain because:-

• It increases the force causing the change in momentum by increasing the time the force acts over.

• It decreases the force causing the change in momentum by increasing the time the force acts over.

• It increases the force causing the change in momentum by deceasing the time the force acts over and changes the momentum

• It decreases the force causing the change in momentum by deceasing the time the force acts over and changes the momentum