Psy Sci HW 4

The change in momentum of an object is equal to the

Impulse that acts on it.

An object in motion is an object that has

Momentum

The impulse-momentum relationship is a direct result of

Newton's second law

A car traveling along the highway brakes to a stop. A greater braking force is required when the car has

all of the above

Bronco's speed increases after he dives from a hovering helicopter. Relative to an observer in the helicopter Bronco's momentum

also increases

Padded dashboards in cars are safer in an accident than non-padded ones because a person hitting the dash has

both of these

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the impulse is

both the same

Which of these two collisions is more damaging; driving into a concrete wall with no "give," or colliding head-on with an identical car moving toward you at your same speed?

both the same

The greater efficiency achieved with the curved blades of a Pelton wheel is due to

bouncing

Which has the greater momentum when moving?

either of these depending on speed

The force of air impact upon the sail of a boat is greater if the air

encounters the sail head-on

Whether a truck comes to a stop by crashing into a haystack or a brick wall, the stopping force is

greater with the brick wall

When a boxer moves into an oncoming punch, the force experienced is

increased

When you can't escape being hit by a fast-moving object, you'll suffer a smaller force if the collision time is

long

Compared with falling on a wooden floor, a wine glass may not break when it falls on a carpeted floor because of

longer time to stop

An iron ball and wooden ball of the same size are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater

momentum

A fan attached to an ice sailcraft stalled on a windless day blows air into the sail that bounces backward upon impact. The boat

moves in the direction of the wind impact force

When Peter tosses an egg against a sagging sheet, the egg doesn't break due to

neither of these

According to the impulse-momentum relationship Ft = change in mv, a falling baseball hits a player with a force F. The t in the equation is the time

of contact of the ball hitting the player

A karate expert executes a swift blow and breaks a cement block with her bare hand. The magnitude of the force on her hand is

the same as the force applied to the block

To catch a fast-moving softball with your bare hand, you extend your hand forward just before the catch and then let the ball ride backward with your hand. Doing this reduces the catching force because the

time of catch is increased

The distinction between impulse and force involves the

time the force acts