W5L3 Example preparation

Two knights have the same momentum but different masses. Select the correct answer to complete this sentence: The heavier knight must be running...

• slower than the lighter knight

• faster than the lighter knight

• at the same speed as the lighter knight

Two balls are rolling down a flat slope. They both have the same momentum, but the blue ball rolls at a faster velocity. Identify what you can conclude about their masses.

• They both have the same masses

• the red ball is heavier

• cannot draw a conclusion

• the blue ball is heavier

Recall the SI unit for impulse

• Newton/second (Ns^-1)

• Newton/minute (Nm^-1)

• Newton-minute (Nm)

• Newton-second (Ns)

Recall what type of graph could you find impulse from

• Acceleration-time graph

• Force-mass graph

• Displacement-time graph

• Force-time graph

A kayaker falls down a waterfall as part of an extreme sports event. Identify if his momentum is conserved as he falls.

• Yes

• No

A Volkswagen and a BMW are driving on an icy (frictionless) road at constant velocity. Suddenly they crash into each other head-on. Identify if momentum is conserved in the collision.

• yes

• no

Recall the main condition required for the law of conservation of momentum to apply.

• No net external force.

• Objects of equal mass.

• A net external force.

• Objects of equal speed

identify which is greater:

• the combined mass of the two nuclei which fuse in nuclear fusion

• the mass of the new nucleus formed through nuclear fusion

Recall the purpose of the moderator

• to speed up neutrons

• to absorb neutrons

• to direct neutrons into the fuel rod

• to slow down neutrons

Select which component of nuclear reactors is used to control the rate of nuclear fission

• control rods

• moderator

• reactor vessel