Physics Homework Questions #3

Momentum is

• a vector quantity

• the product of mass and velocity

• = mv

• All answers are correct

Force acting over a short period of time is described as

• momentum

• impulse

• reaction

• action

When an impulse is applied to an object with momentum, the momentum

• increases

• decreases

• changes

• remains the same

The unit of measurement for momentum is usually

• kgms

• kgm/s

• kg/m/s

• kgm/s/s

Momentum in a system is always

• constant

• conserved

• controlled

• compressed

A car travels along a flat road. The driver takes his foot off the accelerator

Air resistance can appear to change the momentum in the system because

• The particles of air gain the momentum lost by the car

• Collisions with air particles provide an impulse on the car

• The car loses velocity (negative acceleration) while the air particles gain velocity

• all answers are correct

If one object with a velocity x, collides with a second identical object with a velocity of 0 and the two objects stick together, the velocity after the collision will be

• 2x

• x

• x/2

• x + 0

In an elastic collision

• momentum and kinetic energy are conserved

• only momentum is conserved

• only kinetic energy is conserved

• all answers are correct

In an inelastic collision

• momentum and kinetic energy are conserved

• only momentum is conserved

• only kinetic energy is conserved

• all answers are correct

Frictionless conditions are necessary to study momentum because

• everything looks better

• conditions are always frictionless

• friction provides an external force and we'd have to measure the motion of the Earth to see momentum being conserved

• Friction is a condition where momentum is not conserved