Momentum
Which of the following has the largest momentum relative to the Earth's surface?
a pickup truck speeding along a highway
A karate expert executes a swift blow and breaks a cement block with her bare hand. The magnitude of the force experienced by her hand is
identical to the force applied to the block
Compared to falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the
stopping time is longer on the carpet
A rifle of mass 2 kg is suspended by strings. The rifle fires a bullet of mass 0.01 kg at a speed of 200 m/s. The recoil velocity of the rifle is about
1 m/s
A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both move with a combined momentum of
1 unit
A 1000-kg car moving at 10 m/s brakes to a stop in 5 s. The average braking force is
2000 N
If all people, animals, trains and trucks all over the world began to walk or run towards the east, then the
Earth would spin a bit slower
The impulse-momentum relationship is a direct result of
Newton's 2nd law
It is correct to say that impulse is equal to
the change in momentum it produces
When you jump from an elevated position you usually bend your knees upon reaching the ground. By doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. In this way the average force your body experiences is
about 1/10 as great
A car traveling along the highway needs a certain amount of force exerted on it to stop it in a certain distance. More stopping force is required when the car has
all of these
The force on an apple hitting the ground depends upon
all of these
The force that accelerates a rocket in outer space is exerted on the rocket by the
exhaust gases
A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared to the force that stops the car, the force needed to stop the truck is
greater
Momentum is transferred to the ground when an apple falls on it. The momentum absorbed by the ground is
greater than that of the apple only if the apple bounces
When you are in the way of a fast-moving object and can't get out of its way, you will suffer a smaller force of impact if you decrease its momentum over a
long time
A large metal ball is shot from a cannon with a short barrel. If the same ball were to be shot from cannon with a longer barrel, its muzzle velocity would be
more
A 1-N apple falls to the ground. The apple hits the ground with an impact force of about
not enough information given to say
A fan attached to an ice sailcraft stalled on a windless day blows air into the sail that bounces backward upon impact. The boat can
then move in the direction of the wind impact force
According to the impulse-momentum equation Ft = change in (mv), a person will suffer less injury falling on a wooden floor which "gives" than on a more rigid cement floor. The "F" in the above equation stands for the force exerted on the
either the force on the person or the force on the floor
A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun
if the mass of the bullet equals the mass of the gun
If a monkey floating in outer space throws his hat away, the hat and the monkey will both
move away from each other, but at different speeds
An astronaut , floating alone in outer space, throws a baseball. If the ball floats away at a speed of 20 meters per second, the astronaut will
move in the opposite direction, but at a lower speed
Which would produce more force: driving into a very massive concrete wall with no "give," or having a head-on collision at the same speed with an identical car moving toward you with the same speed?
both the same
Two billiard balls having the same mass and speed roll toward each other. What is their combined momentum after they meet?
0
A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball initially at rest. The bowling ball and putty then move with a momentum of
1 kg m/s
A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball that is initially at rest on a frictionless surface. The speed of the putty thereafter is
1/6 m/s
A 5-kg shark swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish swimming toward it at 4 m/s. The speed of the shark after this meal is
1/6 m/s
A ball is moving at 3 m/s and has a momentum of 48 kg m/s. What is the ball's mass?
16 kg
A 4 kg ball has a momentum of 12 kg m/s. What is the ball's speed?
3 m/s
A 5-kg fish swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish at rest. The speed of the larger fish after this lunch is
5/6 m/s
You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum during the time of contact?
both the same
A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is
doubled
Compared to the force that brings a small car to a stop, the force required to bring a heavy truck to a stop
impossible to determine without additional information
Padded dashboards in cars are safer in an accident than nonpadded ones because an occupant hitting the dash has
increased time of impact
To catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because the
time of impact is increased
Recoil is noticeable if we throw a heavy ball while standing on roller skates. If instead we go through the motions of throwing the ball but hold onto it, our net recoil will be
zero