Question

unit 2 test: forces and motion (10/15)
a spacecraft that seems to be motionless in deep space is given some type of quick push. which statement describes what will happen?
the spacecraft will remain still because it only works on earth.
the spacecraft will move and then slowly come to a stop on its own.
the spacecraft will remain still due to air resistance.
the spacecraft will move and not stop until it is met with an unequal and opposite force.

Explanation:

According to Newton's first law of motion (the law of inertia), an object at rest will remain at rest and an object in motion will remain in motion with a constant velocity unless acted upon by an unbalanced force. In deep space, there is no air resistance (since it is a vacuum). When the spacecraft is given a quick push (an unbalanced force), it will start moving. And it will continue moving in a straight line at a constant speed until another un - balanced force acts on it.

• The first option is wrong because the laws of motion (like Newton's laws) apply in space as well as on Earth.
• The second option is wrong because in the absence of a force (like friction or air resistance which are not present in deep - space vacuum), the spacecraft will not slow down on its own.
• The third option is wrong because there is no air resistance in deep space.

Answer:

The spacecraft will move and not stop until it is met with an unequal and opposite force.