Question

which of the following describes an object with zero net force acting on it? choose all that apply.
the motorcycle traveled at a constant speed while making a u - turn.
the car sped up from 50 mph to 65 mph while moving in a straight line.
the moped accelerated while making a left turn.
the spaceship traveled at a constant speed in a straight line.
the truck slowed down while making a right turn.

Explanation:

According to Newton's first law, an object has zero net force when it is in a state of uniform motion (constant speed in a straight line).

• For the motorcycle making a u - turn: Even at constant speed, the direction changes, so there is acceleration and non - zero net force.
• For the car speeding up: There is acceleration (change in speed), so non - zero net force.
• For the moped accelerating (change in speed) and turning (change in direction): Non - zero net force.
• For the spaceship traveling at a constant speed in a straight line: No acceleration (no change in speed or direction), so zero net force.
• For the truck slowing down (change in speed) and turning (change in direction): Non - zero net force.

Answer:

The spaceship traveled at a constant speed in a straight line.