chapter 6
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
The conservation of momentum is most closely related to
newtons third law
The mass of a ball moving at 3 m/s with a momentum of 48 kg m/s is
16 kg
A 5000-kg freight car moving at 2 m/s collides with a 10,000-kg freight car at rest. They couple upon collision and move away at
2/3 m/s
The speed of a 4-kg ball with a momentum of 12 kg m/s is
3 m/s
A 5-kg fish swimming at 1 m/s swallows an absent-minded 1-kg fish at rest. The speed of the larger fish after lunch is
5/6 m/s
A 5000-kg freight car collides with a 10,000-kg freight car at rest. They couple upon collision and move at 2 m/s. What was the initial speed of the 5000-kg car?
6 m/s
The impulse-momentum relationship is a direct result of
Newtons 2nd law
It is correct to say that impulse is equal to
a corresponding change in momentum
Wether a truck comes to a stop by crashing into a haystack or a brick wall, the impulse is greater for what
both the same
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 Cannon recoils while firing a cannonball. The speed of the cannon's recoil is relatively small because the
cannon has much more mass than the cannonball
When bullets are fired from an airplane in the forward direction, the momentum of the airplane is
decreased
The total momentum of a flock of identical birds could be zero only if the birds are
flying in different directions
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 with the force that stops the car, the force needed to stop the truck is greater smaller or the same
greater
When a boxer moves into an oncoming punch, the force experienced is
increased
Padded dashboards in cars are safer in an accident than non-padded ones because passengers hitting the dashboard encounter
lengthened time of contact
A large heavy truck and a small baby carriage roll down a hill. neglecting friction at the bottom of the hill, the baby carriage will have, more or less or the same momentum?
less momentum
To catch a fast moving ball, you extend your hand forward before contact with the ball and let it ride backward in the direction of the ball's motion. Doing this reduces the force of contact on your hand principally because
stopping time is increased
a karate expert executes a swift blow and breaks a cement block with her bare hand. The magnitude of the force is , more less or
the same as the force applied to the block
The force on a dropped apple hitting the ground depends upon
the speed of the apple before impact, wether or not it bounces, time of contact