Unit 1: Force and Motion Review 2022

Which one is the best explanation of energy?

• making transformations

• the ability to do work

• conservation of power

• measuring joules

What happens to gravitational potential energy as a roller coaster moves down a hill?

• It is converted to elastic potential energy.

• It increases.

• It is converted to kinetic energy.

• It remains constant.

When a man walks across the carpet and reaches for the door knob, why does he get shocked?

• There is an electric current in the door knob

• The carpet was exposed to electricity.

• Atoms are moving faster in the door knob than in his hand

• When he drags his feet across the carpet he gains an electric charge, and then the electrons jump from his hand to the doorknob

How does an insulator stop the flow of an electric current?

• Electrons in an insulator do not move readily.

• Insulators convert electric energy to other forms of energy.

• Insulators have too many electrons.

• Insulators have a positive charge so they absorb electrons.

Examine the illustrations of a series circuit and a parallel circuit. How does a parallel circuit differ from a series circuit?

• A parallel circuit has one path for electrons, but a series circuit has more than one path.

• A parallel circuit includes more than one resistor, but a series circuit has one resistor.

• A series circuit has one path for electrons, but a parallel circuit has more than one path.

• A parallel circuit has a power source, but a series circuit does not.

Which item is necessary to make an electromagnet?

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The law of conservation of energy states:

• Energy increases exponentially with time

• Total energy decreases due to energy output.

• Energy cannot be created or destroyed.

• Energy always remains in the same form.

How is power defined?

• the quantity of work accomplished

• the direction of the work

• the total distance an object is moved

• the rate at which work is accomplished

A scientist runs an electric current along a wire. A magnetic compass is placed near the wire. The scientist observes that whenever the current is turned on, the compass needle moves. Why does the compass needle move?

• The current creates an electric field around the wire.

• The current creates a magnetic field around the wire.

• The current adds electric charge to the compass needle.

• The current increases the force of gravity on the compass needle.

When an object moves, stops moving, changes speed, or changes direction, how do scientists describe that condition?

• A balanced set of forces

• Unbalanced forces

• Frictional forces

• Stability factors