Physics HW 3

10.5

The gravitational acceleration on the moon is 1/6 of that on Earth. If an object weighs 63 N on earth, what is it's weight in Newton's on the moon? Round your answer to 1 decimal place

d) continues at a constant velocity

The net force on a moving object suddenly becomes zero. The object then a) stops abruptly b) stops during a short time interval c) changes direction d) continues at a constant velocity e) slows down gradually

c) time of impact is increased

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 a) force of impact is reduced. b) relative velocity is less. c) time of impact is increased. d) time of impact is decreased. e)none of these

e) 4 m/s/s

A net force of 64 N acts on a mass of 16 kg. What is the acceleration of the object? a) 16 m/s/s b) 0.51 m/s/s c) 64 m/s/s d) 9 m/s/s e) 4 m/s/s

66.64 N

A 6.8 kg mass at the Earth's surface weighs N. Round your answer to one decimal place.

c) 16 kg

A ball is moving at 3 m/s and has a momentum of 48 kg m/s. What is the ball's mass? a) 4 kg b) 12 kg c) 16 kg d) 144 kg e) none of these

2.23

A ball is moving at 9.4 m/s and has a momentum of 21.0 kg m/s. What is the ball's mass in kg? Round your answer to 1 decimal place.

495.8

A bicycle of mass 6 kg is being ridden by a bicyclist of mass 61 kg at a speed of 7.4 m/s. What is the total momentum of the bike and bicyclist in SI units? Round your answer to 1 decimal place.

b) 2M

A force accelerates an object of mass M. A second object requires twice the force to produce the same acceleration. What is the mass of the second body? a) M b) 2M c) M/2 d) 4M e) M/4

a) zero

A hockey puck is set in motion across a frozen pond. If friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is a) zero. b) equal to its weight. c) equal to its weight divided by its mass. d) equal to the product of its mass times its weight. e) equal to its mass.

b) The satellite's mass remains constant and its weight decreases

A satellite is sent out in space. Which of the following is true of the satellite as it moves away from the earth? a) The satellite's mass and weight remain equal. b) The satellite's mass remains constant and its weight decreases. c) The satellite's mass decreases and its weight remains constant. d) The satellite's mass and weight decrease. e) The satellite's mass decreases and its weight increases.

c) a net force of zero is acting on the spaceship

A spaceship in deep outer space is moving with a constant speed in a straight line. Which of the following is true? a) A single force is acting on the spaceship in the direction of motion. b) A single force is acting on the spaceship opposite the direction of motion. c) A net force of zero is acting on the spaceship. d) A constant net force is acting on the spaceship.

b) 100 N

An 80 kg man on ice skates pushes a 40 kg boy, also on skates, with a force of 100 N. The force exerted by the boy on the man is a) 200 N b) 100 N c) 50 N d) 40 N e) zero unless the boy pushes back.

b) four times the acceleration of mass 4M

If you apply the same force to objects with masses M and 4M, the acceleration of mass M is a) the same as mass 4M b) four times the acceleration c) one forth the acceleration of mass 4M d) twice the acceleration of mass 4M e) one-half the acceleration of mass 4M

a) increased time of impact

Padded dashboards in cars are safer in an accident than nonpadded ones because an occupant hitting the dash has a) increased time of impact. b) decreased time of impact. c) decreased impulse. d) increased momentum.

b) Objects in motion will stay in motion and objects at rest will stay at rest unless acted upon by an outside force

Which of the following statements is Newton's 1st law? a) Force equals mass times acceleration. b) Objects in motion will stay in motion and objects at rest will stay at rest unless acted upon by an outside force. c) For every action there is an equal and opposite reaction. d) There is an attractive force between any 2 objects in the universe.

a) force equals mass times acceleration

Which of the following statements is Newton's 2nd law? a) force equals mass times acceleration b) Objects in motion will stay in motion and objects at rest will stay at rest unless acted upon by an outside force c) for every action there is an equal and opposite reaction d) there is an attractive force between any 2 objects in the universe

c) for every action there is an equal and opposite reaction

Which of the following statements is Newton's 3rd law? a)Force equals mass times acceleration. b) Objects in motion will stay in motion and objects at rest will stay at rest unless acted upon by an outside force. c) For every action there is an equal and opposite reaction. d) There is an attractive force between any 2 objects in the universe.

5.5

You push on a refrigerator with a force of 11 N and cause the refrigerator to accelerate at 2.0 m/s/s. What is the refrigerator's mass in kg? Round your answer to 1 decimal place.

a) newton

the SI unit of force is the a) newton b)gram c)pound d)kilogram e) meters per second squared