Title: quizzer General knowledge
Course: Physics copy 1

Q: A 3 kg mass going 6 m/s has a momentum of _____ kg.m/s.
A: 18

Q: A 4 kg mass going 6 m/s has a kinetic energy of _____ J.
A: 72

Q: An object at rest may possess:
- velocity
- momentum.
- kinetic energy.
- potential energy.
A: potential energy.

Q: An object in motion need not possess:
- potential energy
- momentum
- kinetic energy.
- velocity
A: potential energy

Q: An object which has momentum must also have:
- acceleration.
- impulse
- kinetic energy
- potential energy
A: kinetic energy

Q: Momentum is most closely related to:
- kinetic energy.
- potential energy.
- impulse.
- power.
A: impulse.

Q: The impulse given to an object is equal to the consequent change in:
- velocity.
- momentum.
- kinetic energy.
- potential energy.
A: momentum.

Q: When the velocity of a moving object is doubled:
- its acceleration is doubled.
- its momentum is doubled.
- its kinetic energy is doubled.
- its potential energy is doubled.
A: its momentum is doubled.

Q: An iron sphere of mass 30 kg has the same diameter as an aluminum sphere of mass 10. 5 kg. The spheres are simultaneously dropped from a cliff. When they are 10 m from the ground, they have identical
- accelerations.
- momenta.
- potential energies.
- kinetic energies.
A: accelerations.

Q: If a shell fired from a cannon explodes in midair:
- its total momentum increases.
- its total momentum decreases.
- its total kinetic energy increases.
- its total kinetic energy decreases.
A: its total kinetic energy increases.

Q: What never changes when two or more objects collide is:
- the momentum of each one.
- the kinetic energy of each one.
- the total momentum of all the objects.
- the total kinetic energy of all the objects.
A: the total momentum of all the objects.

Q: An elastic collision conserves:
- kinetic energy but not momentum.
- momentum but not kinetic energy.
- neither momentum nor kinetic energy.
- both momentum and kinetic energy.
A: both momentum and kinetic energy.

Q: A ball whose momentum is p strikes a wall and bounces off. The change in the ball's momentum is:
- 0.
- p/2.
- p.
- 2p.
A: 2p.

Q: The moving object A collides elastically with the stationary object B. The energy transfer to B is greatest when:
- m_B is greater than m_A.
- m_Bis equal to m_A.
- m_B is less than m_A.
- any of the above occur, depending on the circumstances.
A: m_Bis equal to m_A.

Q: The average momentum of a 70-kg runner who covers 400 m in 50 s is:
- 8.75 kg-m/s.
- 560 kg-m/s.
- 57 kg-m/s.
- 5488 kg-m/s.
A: 560 kg-m/s.

Q: If a rocket of initial mass m is to rise from its launching pad, its initial thrust must exceed
- 1/2 mg
- mg
- 2 mg.
- 12 mg
A: mg

Q: A 30-kg girl and a 25-kg boy face each other on frictionless roller skates. The girl pushes the boy, who moves away at a speed of 1.0 m/s. The girl's speed is
- 0.45 m/s.
- 0.55 m/s.
- 0.83 m/s.
- 1. 2 m/s.
A: 0.83 m/s.

Q: An astronaut whose total mass is 100 kg ejects 1.0 g of gas from his propulsion pistol at a speed of 50 m/s. His recoil speed is:
- 0.5 mm/s
- 5 mm/s
- 5 cm/s
- 50 cm/s
A: 0.5 mm/s

Q: A 10 000 kg freight car moving at 2 m/s collides with a stationary 15 000 kg freight car. The two cars couple and move off at:
- 0.8 m/s
- 1 m/s
- 1.33 m/s
- 2 m/s
A: 0.8 m/s

Q: If two balls collide and rebound at some oblique angle, the momentum of the centre of mass _____. (Changes OR Remains constant)
A: Remains constant / remains constant

Q: According to the principle of conservation of energy (with energy interpreted as including rest energy), energy can be:
- created but not destroyed.
- destroyed but not created.
- both created and destroyed.
- neither created nor destroyed.
- conserved but not transformed.
A: neither created nor destroyed.

Q: A golf ball and a ping-pong ball are dropped in a vacuum chamber. When they fallen halfway down, they have the same:
- speed.
- potential energy.
- kinetic energy.
- rest energy.
- momentum.
A: speed.

Q: In the formula E = m c^2, the symbol c represents:
- the speed of the body.
- the speed of sound.
- the speed of light.
- the rest energy of 1 kg of matter.
- the colour of the wind .
A: the speed of light.

Q: Which of the following is not a unit of power?
- joule-second.
- watt.
- newton-meter per second.
- horsepower.
- joule per second.
A: joule-second.

Q: To keep a vehicle moving at the speed v requires a force F. The power needed is:
- Fv.
- Fv
- 2
- /2.
- F/v.
- F/v
- 2
- .
- none of the above.
A: Fv.

Q: A 2-kg book is held 1 m above the floor for 50 s. The work done is:
- 0.
- 10.2 J.
- 100 J.
- 980 J.
- 19.6 J.
A: 0.

Q: The work done in lifting 30 kg of bricks to a height of 20 m on a building under construction is:
- 61 J.
- 600 J.
- 2940 J.
- 5880 J.
- none of the above.
A: 5880 J.

Q: A 1 N weight has a potential energy of 1 J relative to the ground when it is at a height of:
- 0.102 m.
- 1 m.
- 9.8 m.
- 1 m.
- 32 m.
- none of the above.
A: 1 m.

Q: A total of 4900 J is expended in lifting a 50-kg mass. The mass was raised to a height of:
- 10 m.
- 98 m.
- 960 m.
- 245 000 m.
- 245 000 km.
A: 10 m.

Q: A 1 kg mass has a kinetic energy of 1 J when its speed is:
- 0.45 m/s.
- 1.4 m/s.
- 1 m/s.
- 4.4 m/s.
- 2 m/s.
A: 1.4 m/s.

Q: A 1 N weight has a kinetic energy of 1 J when its speed is:
- 0.45 m/s.
- 1.4 m/s.
- 1 m/s.
- 4.4 m/s.
- 2 m/s.
A: 4.4 m/s.

Q: A 1000-kg car whose speed is 80 km/h has a kinetic energy of:
- 2.52 x 10
- 2
- J.
- 2.47 x 10
- 5
- J.
- 2.42 x 10
- 4
- J
- 3.20 x 10
- 6
- J.
- 3.20 x 10
- 2
- J.
A: 2.47 x 10

Q: Car A has a mass of 1000 kg and a speed of 60 km/h, and car B has a mass of 2000 kg and a speed of 30 km/h. The kinetic energy of car A is:
- half that of car B.
- equal to that of car B.
- twice that of car B.
- four times that of car B.
- one quarter that of car B.
A: twice that of car B.

Q: The mass equivalent of 6 million J is:
- 6.7 x 10^-11 kg.
- 5.4 x 10^-11 kg.
- 6.7 x 10^-3 kg.
- 2.0 x 10^-2 kg.
- 4.0 x 10^-2 kg.
A: 6.7 x 10^-11 kg.

Q: The height above the ground of a child on a swing varies from 0.5 m at the lowest point to 2.0 m at the highest point. The maximum speed of the child is:
- about 5.4 m/s.
- about 7.7 m/s.
- about 29.4 m/s.
- dependent on the child's mass.
- dependent on the weather.
A: about 5.4 m/s.

Q: The 2-kg head of an axe is moving at 60 m/s when it strikes a log. If the blade of the axe penetrates 2 cm into the log, the average force it exerts is:
- 3 kN.
- 90 kN.
- 72 kN.
- 180 kN.
- 360 kN.
A: 180 kN.

Q: A catapult is constructed of an elastic band which just hangs slightly loose between posts 2 m apart. The Roman centurion pulls the band back 1.5 m (perpendicular to the plane between the two posts) with a force of 2000 N. Find the maximum velocity of a 10 kg rock released from this Hookian catapult. (Ignore gravity-horizontal shot).
- 10 m/s
- 14 m/s
- 17 m/s
- 21 m/s
- 25 m/s
A: 14 m/s

Q: The expression Fx gives the _____ done in pushing a spring.
A: work

Q: The expression 0.5 k (x) (x) represents the_____ stored in a spring.
A: energy / potential energy / spring potential energy

Q: A 70 kg diver steps off a 12 m tower. The diver impacts the water at _____ m/s.
A: 15