Physics Review, Please Help ASAP!!! c:?

1. The expression "Every action has an equal but opposite reaction" is often used in everyday speech. A local government may pass a law that is unpopular, which is the action, and some citizens later react by trying to get the law repealed. Which of the following shows why this set of actions differ from Newton's third law in physics?

The action and reaction are not in opposite directions.

The action and reaction do not occur at the same instant of time.

The action and reaction do not act on the same object.

People cannot exert forces.

2. You want to calculate the net force acting on an ice skater who is speeding up while skating. Which of these is a force you would not add in to calculate the net force?

gravity

upward vertical force from the ice that supports the skater

force that the skater exerts on the ground

force exerted on the skater by the ground in reaction to the force the skater exerts on the ground

3. A visitor presses a button to ring the doorbell in an apartment building. Someone on the third floor responds by pushing a button mounted on the wall to release the lock and allow the visitor into the hallway. Assume the force the visitor exerts on the button is the action in Newton's third law. Which of these is the reaction?

force exerted on the third-floor button

force that produces sound within the bell

letting the visitor in

force that the doorbell button exerts on the visitor's finger

4. Suppose you are in a rowboat that is calmly drifting on a lake on a warm summer day. You happen to have a large rock on board. You throw it out of the back of the boat as hard as you can. What happens as a result?

The boat moves forward.

The boat floats quietly in the same place.

The boat moves backward.

The boat moves sideways.

5. A rocket engine expels hot gas at a high velocity out of the back of the rocket. Which of these is the action and reaction pair?

weight of the rocket and weight of the rocket's cargo plus passengers

weight of the rocket and weight of the gas

force that accelerates the gas and force from the gas that accelerates the rocket

mass times acceleration of the engine and mass times acceleration of the rocket cargo and passengers

6. Suppose the force on a baseball when batted is 36 kN in the direction away from the batter. What was the direction and strength of the reaction force?

72 kN away from the batter

18 kN toward the batter

36 kN toward the batter

0 kN

3 Answers

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  • 6 years ago

    1)The action and reaction do not occur at the same instant of time.

    2)force that the skater exerts on the ground

    3)force that the doorbell button exerts on the visitor's finger

    4)The boat moves forward.

    5)force that accelerates the gas and force from the gas that accelerates the rocket

    6)36 kN toward the batter

    Source(s): My Head
  • 3 years ago

    If he was once comfortably standing protecting the bar, the pressure on the ground could be mg + Mg = ninety 4 x 9.Eight + 400 work it out. To accelerate the bar he has to push up with one other force of F = ma = four hundred/9.Eight x a discover a from zero.65 = half a 1.9^2 so a = 0.36 m/s/s F = 14.7 N so force on floor = 1336 N

  • 6 years ago

    1. B

    2. A

    3. A or B (not sure)

    4. A

    5. not sure

    6. C

    I think these are the correct answers but i could be wrong.

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