Science: Energy and Motion

Question 1

What is the equation for gravitational potential energy?

Answer 1

GPE = mass x acceleration of gravity x height

Question 2

What is the equation for work?

Answer 2

Work = force x distance

Question 3

What causes an object that’s not moving to gain kinetic energy?

Answer 3

When energy is transferred to it by another object, for example a ball hits a ball which is not moving, transferring its energy to the resting ball and causing it to move

Question 4

How are energy, motion and speed related?

Answer 4

Energy is needed to move an object, and the higher the energy, the higher the speed of motion

Question 5

Does the speed of an object affect its kinetic energy?

Answer 5

Yes, the higher the speed, the more kinetic energy; the lower the speed, the less kinetic energy

Question 6

What happens to energy in a collision?

Answer 6

Energy is transferred from one object to another in a collision. Energy can also be changed in a collision, for example when a ball hits a solid surface, kinetic energy is changed into sound energy

Question 7

Think about bowling, using a bowling ball versus a tennis ball: what result would be different, and why?

Answer 7

The bowling ball would knock over more pins than the tennis ball because it has more mass, and thus it has more kinetic energy to transfer when it strikes the pins than the tennis ball, even if the 2 balls travel at the same speed

Question 8

What are the 4 ways that energy can be transferred?

Answer 8

Heat, sound, light and electricity

Question 9

What are the ways that heat is transferred?

Answer 9

Conduction, convection and radiation

Question 10

What is conduction? Give an example.

Answer 10

Heat transfer by direct CONTACT - it’s most effective for solids.

Example: frying an egg in a pan - the stove transfers heat to the pan by contact.

Question 11

What is convection? Give an example.

Answer 11

Heat transfer through DENSITY differences - it’s most effective for liquids and gasses.

Example: paper lit on fire will become hot and float up in the air, but will come back down after the fire is distinguished and cools. Or a lava lamp.

Question 12

How is heat transferred by radiation? Give an example.

Answer 12

It does so by WAVE motion - no materials are required for it to travel.

Example: radiation travels from the sun to us and warms up our skin.

Question 13

True or false: all matter can be categorized into moving and non-moving particles.

Answer 13

False: all matter are made of moving particles that have kinetic energy

Question 14

What happens when heat is transferred to an object?

Answer 14

The object’s particles move faster, and therefore the object’s temperature rises

Question 15

What kind of energy do we get from the sun?

Answer 15

We receive some of the sun’s energy as light energy through radiation

Question 16

True or false: sound energy can pass through matter

Answer 16

True: sound energy can pass through solids, liquids and gasses. It travels as a wave.

Question 17

Does a sound with high pitch travel faster or slower than a sound with low pitch?

Answer 17

Faster

Question 18

What is the second law of thermodynamics?

Answer 18

Heat always flows from higher to lower temperature.

Question 19

Moving cars have kinetic energy. When they crash, they stop. Where did the energy go?

Answer 19

It is transferred to other objects, for example the metal frame and exterior of the car. It is also transformed into heat and sound energy.

Question 20

What is example of one form of energy transforming into another?

Answer 20

When we ring a bell, the kinetic energy from our hand is changed into sound energy.

When we turn on the light, electrical energy is changed to heat and light energy.

Question 21

What is a conductor? Give an example.

Answer 21

A material that allows energy to flow through it.

Metals are good conductors, for example copper in electric wires.

Question 22

What is an insulator? Give an example.

Answer 22

A material that does not allow energy to flow through it.

Plastic is a good insulator.

Question 23

What is a resistor?

What happens when electrical energy is pushed through a resistor?

Answer 23

A device that controls the flow of electricity.

When electrical energy is pushed through a resistor, it is often changed to heat and light energy - for example, this is what happens when we turn on a light bulb.

Question 24

What is a source (of electricity)?

Answer 24

It is the starting point of electric energy that keeps a current moving, for example a battery

Question 25

What is to generate?

Give an example of something that self generates electricity.

Answer 25

To produce or make something by itself?

A jellyfish has the ability to self generate electricity to produce light.

Question 26

True or false: the same electric charge attract, while opposites repel

Answer 26

False: opposites attract while the same charge repels

Question 27

Describe what happens when electricity flows through an electric circuit.

Answer 27

A circuit is when electricity travels a complete path between the positive and negative points of a source.

The electricity needs a starting point, or a source, and it flows through a path provided by a conductor to create a complete loop.

A circuit could have a switch to turn the electricity on or off. A circuit could also have something that consumes and uses the electricity, such as a light bulb that changes the electrical energy in from a source into light and heat energy.

Question 28

Draw these electric circuit symbols:

Battery

Wire

Bulb

Buzzer

Motor

Switch On

Switch Off

Answer 28

Show me on paper