Momentum Basics - Level 2 Physics NCEA

Which of the following statements is correct?

• Momentum has only size, its letter is p and its units are kgms^-1

• Momentum has size and direction, its letter is p and its units are kgms^-1

• Momentum has only direction, it's letter is m and its units are kgms^-1

• Momentum has size and direction, it;s letter is m and its units are p

Calculate the momentum of the puck.

• 6 kgms^-1

• 54 kgms^-1

• 540 kgms^-1

• 60 kgms^-1

Why has the blue ball been given a negative velocity in the before the collision diagram?

• To show it's a different mass.

• To show that it is part of the same system

• To show that its direction of movement is opposite to the pink balls one.

• A positive and negative sign is ALWAYS needed in these type of equations.

The blue balls mass is 0.1 kg and its velocity is -0.5 ms^-1. The pink balls mass is 0.3 kg and its velocity is 0.2 ms^-1 Calculate the total momentum of both balls before the collision.

• 1.1 kgms^-1

• -1.1 kgms^-1

• 0.1 kgms^-1.

• -0.1 kgms^-1

After the collision the blue ball 0.1 kg and pink ball 0.3 kg are moving in the + direction together with the same velocity. If their momentum before the collision was 1.6 kgms^-1 calculate their velocity now

• 0.3 ms^-1

• 0.1 ms^-1

• 0.4 ms^-1.

• 1.2 ms^-1

Two carriages before the collision both moving in the same direction. Carriage A is 3 kg moving at 1 m/s, while carriage B is 2 kg and moving at 6 m/s. What is the total momentum before the collision.

• 15 kgms^-1

• 9 kgms^-1

• 12 kgms^-1

• 8 kgms^-1

After the collision carriage A is 3 kg is moving with carriage B is 2 kg in the same direction at the same velocity. Calculate the carriages velocity if the total momentum before is 17.5 kgms^-1

• 3.5 ms^-1

• 2 kgms^-1

• 12 ms^-1

• 8 ms^-1

Change in momentum = final momentum - initial momentum. The tennis balls mass is 0.058 kg. It hits the racket at (-) 20m/s and moves away at (+) 30m/s. Calculate the balls change in momentum.

• 0.01 kgms^-1

• 0.32 kgms^-1

• 0.58 kgms^-1

• 2.32 kgms^-1

Home made cannon (45 kg) and ball (2.5 kg) before the explosion just sitting there. After, the ball is moving at 150 ms^-1 in the direction shown. Calculate the velocity of the cannon. What assumption do you need to make to calculate the answer

• That there is no change in momentum

• That the balls momentum is going to be bigger than the cannons

• That there are no external forces acting and so the total momentum before the explosion is the same as afterwards

• That friction and gravity act on the objects.

Home made cannon (45 kg) and ball (2.5 kg) before the explosion just sitting there. After, the ball is moving at 150 ms^-1 in the direction shown. Calculate the velocity of the cannon.

• - 8.3 ms^-1

• 8.3 ms^-1

• 150 ms^-1

• - 150 ms^-1