Non-Contact Forces

science

How do electrostatic forces work?

They are forces between charged objects — like charges repel, opposite charges attract.

How can you increase the strength of electrostatic forces?

Increase the amount of charge or bring the objects closer together.

Why does rubbing a PVC pipe with a cloth create a charge?

Electrons transfer from one material to the other, leaving one positively charged and the other negatively charged.

Why are electrostatic forces a non-contact force?

They act at a distance — objects don’t need to touch to experience the force.

How do permanent magnets interact?

Like poles repel, opposite poles attract.

How does distance affect magnetic strength?

The further apart the magnets, the weaker the force.

What do field lines look like between two magnets attracting?

Lines connect from north to south pole, showing a strong, joined field.

What do field lines look like between two magnets repelling?

Lines push away from each other, showing a gap where fields do not join.

How do electromagnets work?

Electric current flows through a coil of wire, creating a magnetic field.

What affects the strength of an electromagnet?

Number of coils, amount of current, and presence of an iron core.

How are electromagnets different from permanent magnets?

Electromagnets can be turned on/off and their strength can be changed.

What features are needed in an electric circuit?

A power source, conducting wires, and a load (like a bulb).

How does increasing voltage affect electron movement?

It increases current — electrons flow faster.

State Ohm’s Law.

V = I × R (Voltage = Current × Resistance).

How do you find total resistance in a series circuit?

Add all resistances together: Rtotal = R1 + R2 + …

How do you find total resistance in a parallel circuit?

1/Rtotal = 1/R1 + 1/R2 + …

Compare series and parallel circuits.

Series: same current, one path, if one breaks all stop. Parallel: same voltage, multiple paths, if one breaks others still work.

What are the pros and cons of series vs parallel circuits?

Series: simple but one fault stops all. Parallel: more reliable but uses more energy.

What is an independent variable?

The variable you change on purpose.

What is a dependent variable?

The variable you measure as a result of the change.

How do you interpret scientific data?

Look for patterns, trends, and relationships between variables.