7.1 Mistar content review

Which of the following would increase the attractive force that the balloon exerts on the student's hair?

• changing the side of the balloon facing the hair

• increasing the strength of the charge on the balloon

• increasing the size of the balloon

• the force remains the same if the balloon is moved or the charge is changed

If a frisbee fall out of a tree to the ground, as the frisbee falls

• kinetic energy of the frisbee is increasing and potential energy is decreasing

• kinetic energy of the frisbee is decreasing and potential energy is increasing

• both kinetic energy and potential energy of the frisbee are increasing

• kinetic energy and potential energy of the frisbee both stay the same

In order to get the two ends of magnets marked N to touch, which of the following is true?

• a force must be applied, since two ends marked N repel each other

• a force must be applied, since the two ends marked N attract each other

• the magnets will touch without any force being added

• the magnets can only be made to touch if one of the magnets is reversed

Which of the following statements about electric and magnetic forces is true?

• both electric and magnetic forces can be attractive

• magnetic forces can be repulsive, but electric forces cannot

• electric forces are not affected by distance, but magnetic forces are

• magnetic and electric forces do not interact

Two strong magnets are attracted to each other and are touching, as shown in the diagram below. You pull them apart. What will happen to the force the magnets exert on each other as they move apart?

• as the magnets move apart, they immediately stop exerting a force

• as they move apart, the force exerted increases

• as they move apart, the force exerted decreases

• as the magnets move apart, no change in force occurs

What scientific knowledge and evidence do we need to explain where and how electricity can be generated?

• advantages and disadvantages of each energy source

• which environment or locations will work for each type

• how the energy source can be generated

• all of the above

Which of the following is an example of energy of motion being transformed into electrical energy?

• magnets spinning, which turns a nail with a coil, which then turns on a lightbulb

• eating food and then running

What are the necessary parts of an electrical generation system?

• coils of wire and moving magnets

• coils of wire, moving magnets, water

• coils of wire, moving magnets, and solar radiation

What causes the gravitational potential energy within a system to change?

• the height of the object

• the speed of the object

• the time

The location of an electric generator affects its ability to capture energy from its surrounding

• true

• false