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