Forces and Fields
A push or pull that can change an object’s motion.
What is a force?
This negatively charged particle can move from one object to another.
What is an electron?
A plastic comb becomes charged after being rubbed against dry hair.
What is friction?
Every magnet has these two poles.
What are north and south poles?
A temporary magnet created when electric current flows through a coil of wire.
What is an electromagnet?
Gravity, electric force, and magnetic force can act between objects without this occurring.
What is contact or touching?
An object that gains electrons develops this type of net charge.
What is a negative charge?
A charged metal rod touches a metal sphere and transfers electrons to it.
What is conduction?
This happens when the north pole of one magnet is placed near the south pole of another magnet.
What is attraction?
Adding more wire turns around an iron nail usually causes this change in an electromagnet.
What is an increase in magnetic strength?
This is the region around an object where another object can experience a push or pull.
What is a field?
These materials allow electrons to move and spread easily.
What are conductors?
A charged balloon is held close to a neutral metal can without touching it, causing charges inside the can to rearrange.
What is induction?
Two north poles are brought close together. Describe the interaction.
What is they repel or push apart?
This device changes electrical energy into mechanical energy or motion.
What is a motor?
Two identical objects are placed at different distances from Earth. Object A is closer to Earth than Object B. This object experiences the stronger gravitational force.
What is Object A?
Extra electrons are placed on one end of a metal rod. Describe what happens to the electrons.
What is they spread throughout the metal rod?
One material gains electrons while another loses electrons as the two materials are rubbed together. Explain why the materials develop opposite charges.
What is electrons transferred from one material to the other, making one negative and the other positive?
A paper clip moves toward a magnet before touching it. This provides evidence that this exists between the objects.
What is a magnetic field?
This device changes mechanical energy or motion into electrical energy.
What is a generator?
Planet X has twice as much mass as Planet Y. A satellite is the same distance from both planets. Explain which planet exerts the greater gravitational force and why.
What is Planet X, because greater mass produces a stronger gravitational force?
Extra electrons are placed on one area of a rubber balloon. Explain why they remain near that area instead of spreading across the balloon.
What is rubber is an insulator, so its electrons cannot move freely?
A negatively charged rod is brought near a neutral metal sphere. Electrons move toward the far side of the sphere. Name the charging process and explain why the near side attracts the rod.
What is induction; electrons move away, leaving the near side temporarily more positive?
A student measures the number of paper clips attracted by a magnet from distances of 1 cm, 3 cm, and 5 cm. Predict the pattern in the data.
What is the magnet will attract fewer paper clips as distance increases because magnetic force becomes weaker?
A student tests whether the number of wire turns changes electromagnet strength. The student uses 10, 20, and 30 turns. Name the independent variable and one variable that should remain constant.
What is the number of wire turns is the independent variable, while the battery, core, wire type, or testing method should remain constant?