Unit 2 Review

Based on the diagram of a roller coaster car on a roller coaster track, which statement is TRUE?

• The car at point A has more kinetic energy than the car at point C.

• The car at point C has less kinetic energy than the car at point B.

• The car at point C has more kinetic energy than the car at point B.

• The car at point D has less potential energy than the car at point B.

How is thermal energy transferred within a metal wire?

• Convection: by the motion of electrons through the wire

• Conduction: by the transfer of electrons from atom to atom

• Conduction: by the transfer of kinetic energy between colliding particles

• Convection: by the transfer of potential energy between colliding particles

For homework, students were asked to investigate examples of energy conversions. While riding home from school, Max reaches the top of a hill and begins to coast without pedaling. The bicycle speeds up as it descends to the bottom of the hill and then slows down as it continues up a second hill, where it stops.

Which of these sequences should Max use to describe the energy change of the bicycle from the top of the hill until it stops?

• potential-kinetic-kinetic

• kinetic-potential-potential

• kinetic-potential-kinetic

• potential-kinetic-potential

A student investigated the containers of water shown in the pictures. The student placed Container 1 in the middle of Container 2. The student measured the temperature of the water in each container after 30 minutes.

• The water in container 1 rose to 70C while the water in container 2 decreased to 30C. Heat was transfered from container 2 to container 1 by radiation and convection.

• The water in container 1 rose to 60C while the water in container 2 decreased to 60C. Heat was transfered from container 2 to container 1 by conduction and convection.

• The water in container 1 rose to 40C while the water in container 2 increased to 100C. Heat was transfered from container 2 to container 1 by conduction and radiation.

• The water in container 1 rose to 90C while the water in container 2 decreased to 60C. Heat was transfered from container 2 to container 1 by conduction and convection.

The toaster has an alarm that goes off when the toast is ready. Which best describes the type of energy used by the alarm?

• heat energy

• light energy

• mechanical energy

• sound energy

Mady Jane places several metal chairs and wooden chairs in a room for a long time. She has classmates sit in the chairs and determine which chairs are colder. They determine that the metal chairs are colder.

Why does a metal chair feel colder than a wooden chair?

• The metal chair conducts heat from your body better than the wooden chair.

• The metal chair conducts cold into your body better than the wooden chair.

• The wooden chair radiates heat from the chair to your body.

• The metal chair radiates heat from your body to the chair.

A teacher demonstrates a chemical reaction. A student observes that the test tube in which the reaction occurs becomes warm.

What is the source of the thermal energy generated by the reaction?

• Energy stored in the reactants is released during the reaction as thermal energy making the test tube warm.

• Breaking bonds of the reactants takes energy. The energy is felt as a temperature increase in the test tube.

• Kinetic energy absorbed by the reaction generates thermal energy due to the moving particles. This energy is felt as heat from the test tube.

• Potential energy absorbed by the reaction generates thermal energy due to the moving particles. This energy is felt as heat from the test tube.

Which statement BEST describes the change in energy during motion of the pendulum?

• The kinetic energy at point 3 increases as it moves to point 4.

• The potential energy at point 2 increases as it moves to point 4.

• The kinetic energy at point 1 is equal to the potential energy at point 3.

• The potential energy at point 1 is equal to the potential energy at point 3.

When would the wind-up toy have the GREATEST potential energy?

• After it is wound

• Before it is wound

• While it is in motion

• When it has come to a stop

Which statement describes the energy of the objects in the image?

• The falling water has potential energy and the rock over which it flows has kinetic energy.

• The pool of water has more kinetic energy and the falling water has more potential energy

• The water has potential energy at the top of the waterfall and increasing kinetic energy as it falls.

• The water at the top of the fall has kinetic energy that becomes potential energy as it falls into the pool.