Motion RevisionMotion Revision

If the International Space Station is 350km up (7000km from the Earth's centre) and orbits in 90 minutes, how

fast is her toolbox travelling?

Circumference = 2πrSpeed = distance / time

Distance Time Graphs

►Describe the motion of the object during regions a b c

Velocity and Acceleration

1. Velocity and speed are different; one of them has a direction, but which one?

2. What is the standard unit for speed?

3. What is the standard unit for acceleration?

• Acceleration = change in velocity

• time taken for change

Velocity Time Graphs

►This graph shows the acceleration of a rocket, how fast is it accelerating?

Using Graphs

►Calculate the distance travelled by this object (remember, it’s the area under the line).

Speed of Light Questions

►Light speed = 300,000 km/s►Light takes the following time to get to:►The Moon = 1.5 seconds►The Sun = 8 minutes►The nearest other star = 4 years►The nearest galaxy = 2,500,000 years►Now work out the distances!

Speeding up and Speeding up and slowing downslowing down

Revision

Forces Between Objects Questions

1. If a boy pushes a shopping trolley with a force of 100N, what force is exerted on the boy by the trolley, and in which direction?

2. We say that the forces are _________ and _________.

3. What is a terminal velocity? Give an example.

Resultant Force Questions

1. A plane is flying at a steady speed at the same altitude, draw a diagram of the forces acting on it, forces represented as arrows.

2. The plane decelerates and descends, draw another diagram of the forces acting on it.

3. In the two above questions, describe the horizontal and vertical resultant forces.

Force and Acceleration Questions

1. F=ma; rearrange to find mass and acceleration.

2. Copy and complete the table:

Force (N) (A) 100 20000 50 (E)

Mass (kg) 70 (B) 1000 (D) 200

Acceleration (m/s2)

10 10 (C) 43 15

On the Road Questions

1. List the factors that would increase braking distance.

2. List the factors that would increase thinking distance.

3. List the factors that would decrease thinking distance.

Stopping Distance Stopping Distance

= Thinking Distance + Braking Distance= Thinking Distance + Braking Distance

Falling Objects

• Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg)

1. What is the weight of a 60kg person on Earth/Mars/Moon?

2. What is the weight of a 5kg cat on Earth/Mars/Moon?

3. What is the weight of a 1200kg car on Earth/Mars/Moon?

Earth ~10N/kgEarth ~10N/kg

Mars ~4N/kgMars ~4N/kg

Moon ~1.5N/kgMoon ~1.5N/kg

Work, Energy and Momentum

Revision

Energy and Work

• Copy: Work done = Force x Distance

(J) (N) (m)

1. How much work is done when a pupil lifts their 7kg bag onto a desk 1.2m high?

2. How much work does a teacher do when carrying 15kg of books 80m?

Kinetic Energy

Copy: Kinetic Energy = ½ x Mass x Velocity2

(J) (kg) (m/s)

1. A 1.2 ton car travelling at 30m/s has a Kinetic energy of?

2. A 10kg toolbox travelling at 4km/s has a kinetic energy of?

Momentum

Copy: momentum = mass x velocity (kg m/s) (kg) (m/s)

1.Calculate the momentum of a 60kg person running at 5m/s

2.Calculate the momentum of a 80kg person walking at 2m/s

Collisions and Explosions

In a collision:

momentum before = momentum after

In an explosion, where A and B are ejected:

Momentum of A = -Momentum of B

Or Momentum of A + Momentum of B = 0

Changing Momentum

• Force = Change in momentum

time taken

• Therefore, the more time an impact takes, the more force is exerted.

• Slowing down an impact makes it safer, for example: air bags, car crumple zones, mats in the gym, etc.

Questions

• Turn to page 222 in the books and work through the green Summary Questions.

Static Electricity Revision

Charge

1. Electrical charge can either be ______ or _______.

2. Like charges _______.3. Unlike charges _________.4. To become _______ a insulator must

lose electrons.5. To become _______ a insulator must

gain electrons.

Moving Charge

1. Define electrical current.2. Describe what happens when a

charge is earthed.

Uses of static

• Can you think of 3 uses of static? Discuss with a partner.

• Can you think of 2 dangers caused by static? Discuss with a partner.

Current Electricity Revision

Electric Circuits

• Name these circuit symbols:

• 1• 2• 3• 4• 5• 6

• 7• 8• 9• 10• 11

Resistance

• Resistance (Ω) = Voltage (V)

Current (A)

• The current through a wire is 3A when the potential difference is 9V, what is the resistance of the wire?

Current-Potential Difference Graphs

• Which graph links to which component?

1. Resistor at constant temperature

2. Diode

3. Filament Lamp

A

B C

Series Circuits

• http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/electricity/circuitsrev5.shtml

Parallel Circuits

• http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/electricity/circuitsrev6.shtml

Mains Electricity Revision

Alternating Current

1. Alternating current repeatedly reverses its ___________.

2. A torch battery could have a voltage of ___.

3. A car battery may have a voltage of ___.

4. Mains electricity is ___.

Cables and Plugs

1. Why are the wires made of metal?

2. Why is the case made of plastics?

3. Why is there a fuse?

4. Is the fuse in series or parallel?

5. Why is there an earth wire?

Fuses

1. Why do we use fuses?

2. What happens inside a fuse if too much current flows?

3. Should the rating of the fuse by slightly lower, slightly higher or exactly the current of the appliance?

4. How are circuit breakers different to fuses?

Electric Power and Potential Difference

• Power (W) = Current (A) x Voltage (V)

• Power (W)= Energy transferred (J)

time (s)

1. A computer transfers 150000J of energy when used for 5 minutes, what is its power use?

Electrical Energy and Charge

• Charge flow (C) = Current (A) x time (s)

• Energy (J) = Voltage (V) x Charge flow (C)

1. Calculate the charge flow when the energy is 150J and the voltage is 3V

2. Calculate the maximum charge flow when 5A fused computer is used for 30 minutes.

Nuclear Physics

Revision

Nuclear Reactions

1. Which decay emits an electron?2. Which decay emits a helium nucleus?3. Which decay changes the atomic number by

+1?4. Which decay doesn’t change the mass

number?5. What symbols represent alpha and beta?6. What are the 5 main sources of background

radiation?

The Discovery of the Nucleus

1. Where is most of the mass in an atom?

2. What charge does the nucleus have?

3. What charge does an alpha particle have?

4. {H} Write down bullet points on how the nucleus was discovered.

Nuclear Fission

1. What isotopes are typically used for fission?

2. Is a chain reaction wanted or unwanted?

3. What triggers fission of a nucleus?

4. Why are control rods used in reactors?

Nuclear Fusion

1. What happens to 2 nuclei when fusion occurs?

2. What is plasma?3. How is the plasma contained in the

fusion reactor?4. What happens to the nuclei if the plasma

is not hot enough when they approach each other?