PS-6 Test Review

What must increase to effect the KE of an object the most?

The velocity because it is squared in the formula… KE= ½ mv2

A car transfers chemical potential energy to _______ energy.

Mechanical energy

What effects the GPE of an object?

Gravity, mass, & height

What is the SI Unit for energy

Joule (J)

According to the law of conservation of energy, energy in the universe cannot be created or destroyed, therefore it is _________.

transferred

How much work is done when a 10N force is applied over a 3 meter distance?

W = f x d = 10N x 3m = 30 J

For an object to have KE, it must be________________.

moving

Where does a pendulum have:

Maximum KE? Maximum PE? Increasing KE? Increasing PE?

What are the requirements to do work?

An object must move

The motion of the object must be in the same direction as the applied force on the object

You rub a balloon against your sweater: What charge does the balloon have and why?

Negative – it picked up electrons from your sweater

What charge does the sweater have and why? Positive – it has less electrons after

transferring some to the sweater By what method was charge transferred?

friction

What is the difference?

Charge by conduction Charging an object by contact

Charge by induction Charging an object by holding a

charged object near it

Which of the above is lightning and why? Charge by induction…the clouds and

the ground don’t touch each other

What is static electricity?

The accumulation of excess electric charges on an object

Static meaning no motion

Electroscope

What does it detect? An unknown electric charge

When the leaves spread apart what has happened? The charges are the same and repel

How does it detect an unknown charge? leaves come together if the charges

are different (attract)and will spread apart if like charges (repel)

Electric Current What is it?

The flow of electrons through a conductor How is it measured?

Amperes (A) ______ is the force or push for electrons in a circuit

and is measured in ______. Voltage, Volts (V)

______ is electrical friction and is measured in _________. Resistance, Ohms ()

Ohm’s Law

What is it? The current in a circuit = voltage

divided by the resistance

What is the current in a circuit with a 6 volt battery and 2 ohms of resistance? I = V/R = 6V / 2 = 3 A

Electric Circuits A _______circuit has one path for electrons

to flow. Series

A _______ circuit has more than one path for electrons to flow. Parallel

Series Circuit

What happens if a bulb is removed? All the lights go out – open circuit

If you add a bulb what happens to: Voltage - increases Current - decreases Resistance - increases

Parallel Circuit What happens if a bulb is removed?

The other bulbs stay lit & are brighter If a path is added, what happens to: Voltage – Stays the same Current - Increases w/ each path Resistance – decreases w/ each path

Resistance in a circuit is effected by what 3 things? Large diameter – less resistance Long wires – greater resistance Increase in temperature – increase

resistance

Electromagnet

What is it? Electricity runs through a wire and

causes a magnetic field

What can be done to increase it’s strength? Coil more wire around the object

In electromagnetic induction, electric current is produced when a loop of wire is moved through a ___________. Magnetic field

What is the difference between AC and DC current?

AC =current moves back and forth

DC = flows in one direction

A generator converts _______ energy to ________ energy. Mechanical / Electrical

An electric motor converts __________ energy to ________ energy. Electrical / Mechanical