Gravitational Fields
What is a gravitational field?
A region around an object (like Earth) where it exerts a force on other objects without touching them.
What is an electric field?
A region around a charged object where it can exert a force on other charged objects without contact.
What is a magnetic field?
A region around a magnet where it exerts a force on other magnets or magnetic materials without touching them.
What is electromagnetism?
The interaction where electricity creates magnetism, and moving magnets create electricity.
Name three types of fields that exert forces without contact.
Gravitational, electric, and magnetic fields.
How does the distance between two objects affect the gravitational force?
As distance increases, the gravitational force decreases.
Do opposite charges attract or repel in an electric field?
They attract.
What happens when you bring the north pole of one magnet near the south pole of another?
They attract each other.
How can you make a magnetic field with electricity?
Run an electric current through a wire or coil.
How can you tell if a force is attractive or repulsive in an investigation?
Observe if objects move closer (attraction) or apart (repulsion).
Why do a feather and a rock fall at the same rate in a vacuum?
In a vacuum, there’s no air resistance, so Earth’s gravitational field accelerates all objects at the same rate (9.8 m/s²).
What happens to the electric force if you double the distance between two charged objects?
The force decreases from its original strength.
Name two variables that affect the strength of a magnetic field.
Distance from the magnet and the magnet’s strength.
What happens to an electromagnet’s strength if you add more loops to the coil?
The magnetic field gets stronger.
What data might you record in an investigation of two magnets?
Changes in motion (e.g., how far they move), push/pull sensations, or distance at which attraction starts.
Describe an investigation to test how mass affects gravitational force.
Drop objects of different masses (e.g., a marble and a bowling ball) and observe if they hit the ground at the same time in a controlled setting.
Describe an investigation using pith balls to show electric fields.
Rub a balloon to charge it, then hold it near pith balls. Observe if they move toward (attraction) or away (repulsion) to identify the charge.
Design an investigation to test how distance affects magnetic force.
Use a magnet and a paperclip. Measure how far away the magnet can pull the clip and record changes as distance increases.
Describe an investigation to show electromagnetic induction.
Move a magnet in and out of a wire coil connected to a light bulb. Observe if the bulb lights up when the magnet moves.
Design an investigation to test why Earth’s gravitational field affects all objects equally.
Drop objects of different weights (e.g., a coin and a feather) in air and a vacuum. Compare fall times and motion.
Explain why astronauts float in space but still experience Earth’s gravitational field.
They’re in free fall toward Earth, but their orbit keeps them moving forward, so they don’t feel a push or pull against their bodies.
How does the magnitude of a charge affect the electric force between two objects?
A larger charge increases the electric force.
Explain how a compass can show the polarity of a magnetic field.
The compass needle (a magnet) aligns with the field, pointing toward the south pole and away from the north pole.
Explain how a generator uses magnetism to create electricity.
A coil spins in a magnetic field, inducing an electric current through motion.
Predict what happens if you increase the current in an electromagnet near a compass.
The compass needle deflects more because the magnetic field strengthens.