Chapter 6: Momentum Flashcards
Which of the following has the largest momentum relative to the Earth’s surface: a) a pickup truck speeding along a highway; b) a dog running down the street c) a tightrope walker crossing Niagara Falls d) the Science building on campus.
a) a pickup truck speeding along a highway
When two objects interact, conservation of momentum is most closely related to: a) Newton’s 1st law; b) Newton’s 2nd law; c) Newton’s 4th law; d) Newton’s 3rd law.
d) Newton’s 3rd law.
Suppose that a tiny gun made of a strong but very light material fires a bullet that is more massive than the gun itself. For such a weapon: a) recoil problems would be lessened; b) both conservation of energy and momentum would not hold; c) conservation of momentum would not hold; d) conservation of energy would not hold; e) the target would be safer than the shooter.
e) the target would be safer than the shooter.
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 a greater: a) speed; b) acceleration; c) momentum; d) none of these; e) all of these.
d) none of these.
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.
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: a) short time; b) same way either way; c) long time.
c) long time.
A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun; a) if the mass of the bullet equals the mass of the gun; b) because velocity is conserved; c) because momentum is conserved; d) because both velocity and momentum are conserved; e) none of these.
a) if the mass of the bullet equals the mass of the gun.
Compared to falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the: a) stopping time is longer on the carpet; b) carpet provides a smaller impulse and a longer time; c) carpeted floor provides a smaller impulse; d) stopping time is shorter on the carpet.
a) stopping time is longer on the carpet.
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.
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: a) more than the force applied to the block; b) identical to the force applied to the block; c) less than the force applied to the cement block; d) impossible to predict without additional information; e) zero.
b) identical to the force applied to the block.
