7th Grade Semester 1 Exam

How many variables should be tested in a correctly performed scientific experiment?

• Zero

• One

• Two

• Three

In a controlled scientific experiment, the _______ variable is manipulated or tested by the researcher.

• Control

• Dependent

• Constant

• Independent

Why do scientists attempt to replicate the results of other scientist's experiments?

• To learn from them.

• To take the experiment one step further.

• Because it is easier than coming up with their own idea.

• To determine if the original results were accurate.

Mechanical energy is the sum of two types of energy-kinetic energy and potential energy of position. Which of the following is an example of an object that has kinetic energy?

• A. A snail crawling across a leaf.

• B. A computer monitor sitting on a desk.

• C. A tightly wound spring in a windup toy.

• D. A roller coaster car just before it goes downhill.

Which set of words below make the following statement about energy correct? "Energy cannot be ______ or ______. Energy ______ from one form to another."

• Increased, decreased, flows

• Added, removed, moves

• Created, destroyed, transforms

• In motion, at rest, cannot change

A ball is sitting at the top of a ramp. As the ball rolls down the ramp, the potential energy of the ball decreases. What happens to the potential energy as the ball moves?

• It is lost as gravitational energy.

• It is converted to kinetic energy.

• It is destroyed as the ball moves.

• It is used to make the ball slow down.

The heat from the Sun travels through space to the Earth. What method of heat transfer is being described?

• Radiation

• Conduction

• Convection

• Condensation

John puts a straw into a glass of water. He notices that the straw appears to be broken when he looks through the glass and the water from the side. Which term best explains why the straw looks like it is broken?

• Absorption

• Refraction

• Scattering

• Transmission

Ian reaches for a flashlight to switch it on. Which shows the energy conversion that takes place when the flashlight is turned on in correct order?

• electrical --> chemical --> light energy

• electrical --> chemical --> kinetic energy

• chemical --> electrical --> light energy

• chemical --> electrical --> kinetic energy

Jorge heats a pot of water over the flame on his stove. Overtime the water heats to boiling. Which process is indicated by the letter Y?

• Conduction

• Convection

• Insulation

• Radiation