7th Grade Electromagnetic Force Review

Topic: Electromagnetic Force Benchmark Review

EQ: What will be on my Science Benchmark on Thursday?

Do Now: Set up notes and Word Document for screenshots.

Topic: Investigation 1 What is Force?

EQ: How are force and motion related?

• A force is a push or a pull.

• The metric unit for force is the newton (N).

• Friction is a force that acts to oppose a force acting to put a mass in motion.

• Net force is the sum of the forces acting on a mass.

Multiple Choice

Which of the runner's accelerated during the race?

• Runner A

• Runner B

• Runner C

• Runner D

Multiple Choice

What is the net force on the object and which way would it move?

• 13 N to the LEFT

• 17 N to the RIGHT

• 0 N no movement

• 4 N to the LEFT

Multiple Choice

A student pushes against a wall with 20 N of Force and the wall does not move. In this case, the wall exerts _.

• 0N of force

• 20 N of force

• More than 20 N of force

• Less than 20 N of force

Multiple Choice

Which of the following examples demonstrates balanced forces on an object?

• An apple falling from a tree.

• A ball rolling down a ramp.

• A binder resting on a table.

• A football thrown into the air.

Topic: Investigation 2 The Force of Magnetism

EQ: How can we describe magnetic force?

• Magnets stick to (attract) objects that contain iron.

• All magnets have two poles, a north pole on one side and a south pole on the other side.

• Like poles of magnets repel each other; opposite poles attract.

Topic: Investigation 2 The Force of Magnetism

EQ: How can we describe magnetic force?

• Magnets are surrounded by an invisible magnetic force field, which acts through space and through all nonmagnetic materials.

• Magnetic materials may become temporary magnets when they interact with magnetic fields.

• The magnitude of the magnetic force between two interacting magnetic fields decreases as the distance between them increases.

Multiple Choice

If you cut a permanent magnet into 4 pieces, you will have _.

• 4 temporary magnets

• 4 smaller permanent magnets

• 2 north poles and 2 south poles

• 4 objects that are no longer magnets

Multiple Choice

A bar magnet is broken into 2 pieces. What is true about the force between the broken pieces if they face each other with a small separation?

• There is magnetic attractive force between the 2 broken pieces.

• There is gravitational attractive force between the 2 broken pieces.

• There is no force between the 2 pieces because they've been demagnetized.

Multiple Choice

A student discovered that when she touched a nail to a magnet, the nail picked up a paper clip. What type of magnet did the student create?

• The student created a temporary magnet by inducing magnetism in the nail.

• The student created a permanent magnet that was able to pick up the nail.

• The paper clip is made of steel and is a permanent magnet.

Multiple Choice

A student observes that he is able to move a magnet using another magnet without either of them touching. What is this demonstration an example of?

• The force of magnetism (magnetic field) goes through some materials.

• Magnetic fields always attract each other.

• The bottom magnet makes the top magnet into a temporary magnet.

Topic: Investigation 3 Electromagnetism

EQ: How are electricity and magnetism related?

• Energy transfers through an electric circuit from a source to components.

• A magnetic field surrounds a wire through which electric current is flowing.

• The magnetic field produced by a current carrying wire can induce magnetism in a piece of iron or steel.

Topic: Investigation 3 Electromagnetism

EQ: How are electricity and magnetism related?

• An electromagnet is made by sending electric current through an insulated wire wrapped around an iron core.

• The strength of magnetism induced in the core of an electromagnet increases with the number of winds of wire, the amount of electric current flowing in the wire, and the iron content of the core.

Multiple Choice

When you close the switch, the battery transfers to the lightbulb by what?

• light

• magnetism

• gravity

• electricity

Multiple Choice

Which circuit will light the bulb?

• Circuit A

• Circuit B

• Circuit C

• Circuit D

Multiple Choice

A student set a compass on top of a wire not yet connected in a circuit. When she connected the wire to the positive side of the D-cell, the compass needle moved. Why did the compass needle change position when the circuit was closed?

• When the circuit is complete, electricity also runs through the compass.

• A magnetic field surrounds a wire when electric current flows through it.

• The compass-needle change indicates the potential energy in the D-cell.

• The magnetic poles of the D-cell reversed, causing the compass needle to move.

Multiple Choice

The graph shows the results of an investigation with an electromagnet. What pattern does the data show?

• The thinner the wire, the fewer nails lifted.

• The thicker the wire, the fewer nails lifted.

• The gauge of the wire does not affect how many nails can be picked up.

Topic: Investigation 4 Energy Transfer

EQ: How do humans use energy?

• An electric motor is designed with a commutator that acts as a switch turning on and off an electromagnet.

• Electric generators transfer energy from kinetic energy to electrical energy.

Topic: Investigation 4 Energy Transfer

EQ: How do humans use energy?

• Energy cannot be created or destroyed, only transferred.

• Every energy use can be described as a sequence of energy transfers.

• Energy sources can be categorized as renewable or nonrenewable.

Homework

• Study for Science Benchmark on January 28

• All late work is due by February 3rd at 3PM

• Review this Quizizz for Homework and add to your Cornell Notes.