Transcript 2 mark - Durrington High School

Quick Questions 
1.
2.
3.
4.
What is the difference between velocity & speed?
What is the definition of acceleration?
What is the unit for acceleration?
What is the equation and formula triangle to calculate
speed?
5. How would you calculate the resultant force acting on
the object below?
180N
120N
250N
The front crumple zone of a car is tested at a road traffic laboratory. This is done by
using a remote control device to drive the car into a strong barrier. Electronic sensors
are attached to a dummy inside the car.
1. Draw an arrow in Box 1 to show the direction of the force that the car exerts
on the barrier.
2. Draw an arrow in Box 2 to show the direction of the force that the barrier
exerts on the car.
The diagrams, A, B and C, show the horizontal forces acting on a moving
car.
Match each diagram to the description of the car’s motion at the moment
when the forces act.
stationary
A
constant speed
B
slowing down
C
accelerating forwards
The diagram shows the horizontal forces that act on a moving motorbike.
1. Describe the movement of the motorbike when force A equals force B.
(2 mark)
2. What happens to the speed of the motorbike if force B becomes
smaller than force A?
(1 mark)
How do you calculate the acceleration?
GRADIENT
How do you calculate the distance travelled? (higher tier only)
AREA UNDER THE LINE
Gradient = height of the triangle
base of triangle
height
base
Higher Tier ONLY
To find the distance travelled on a velocity-time
graph you calculate the area under the line
Area of rectangle/square = height x base
Area of triangle = height x base
2
A car travelling along a straight road has to stop and wait at red traffic lights. The graph shows how the velocity of
the car changes after the traffic lights turn green.
1. Calculate the distance the car travels while accelerating. (3 marks)
2. Calculate the acceleration of the car. (4 marks)
Show clearly how you work out your final answer and give the units.
Foundation Tier
Part of a bus route is along a high street. The distance-time graph shows how far the
bus travelled along the high street and how long it took.
1. Between which
two points was the
bus moving with the
slowest speed?
(1 mark)
2. Between which
two was the bus not
moving?
(1 mark)
Time in seconds
3. The mass of the car is 900kg. The car is accelerating at
12m/s2
Calculate the force used to accelerate the car. Show clearly
how you work out your final answer.
(3 marks)
The diagram shows a boat pulling a water skier.
1. The arrow represents the force on the water produced by the engine
propeller. This force causes the boat to move.
Explain why.
(2 marks)
2. The boat accelerates at a constant rate in a straight line. This causes
the velocity of the water skier to increase from 4.0 m/s to 16.0 m/s in 8.0
seconds.
(i)
Calculate the acceleration of the water skier and give the unit.
(3 marks)
(ii) The water skier has a mass of 68 kg.
Calculate the resultant force acting on the water skier while accelerating.
(2 marks)
What makes up a stopping distance?
Thinking distance + braking distance
= stopping distance
A car driver sees a dog on the road ahead and has to make an emergency stop.
The graph shows how the speed of the car changes with time after the driver first sees the dog.
1. Which part of the
graph represents the
“reaction time” or
“thinking time” of the
driver? (1 mark)
2. What is the thinking
time of the driver?
(1 mark)
3. Calculate the distance
travelled in this
thinking time. (HT only)
(3 marks)
4. Calculate the
acceleration of the car
after the brakes are
applied. (4 marks)
Higher Tier ONLY
A car driver sees a dog on the road ahead and has to make an emergency stop.
The graph shows how the speed of the car changes with time after the driver first sees the dog.
4. Calculate the
acceleration of the car
after the brakes are
applied. (4 marks)
5. Calculate the distance
travelled by the car
during braking.
(4 marks)
6. The mass of the car is
800 kg. Calculate the
braking force.
(4 marks)
Copy and complete the Venn diagram to show the
factors that affect thinking and braking distances
Thinking
distance
Braking
distance
Copy and complete the Venn diagram to show the
factors that affect thinking and braking distances
Thinking
distance
Braking
distance
tiredness
brakes
road
conditions
drugs
alcohol
distractions
speed/
velocity
weather
conditions
tyres
distance
energy
force
time
1. Use words from the box to complete the sentence.
The stopping distance is found by adding the distance the
car travels during the driver’s reaction
........................................ and the distance the car travels
under the braking ........................................ .
(2 marks)
2. Name three factors, other than weather conditions,
which would increase the overall stopping distance of a
vehicle.
(3 marks)
1. A car is travelling at a speed of 20 m/s when the driver applies the brakes.
The car decelerates at a constant rate and stops. The mass of the car and
driver is 1600 kg.
(i) Calculate the kinetic energy of the car and driver before the brakes are
applied.
(2 marks)
(ii) How much work is done by the braking force to stop the car and driver?
(1 mark)
(iii) The braking force used to stop the car and driver was 8000 N.
Calculate the braking distance of the car.
(2 marks)
(iv) The braking distance of a car depends on the speed of the car and the
braking force applied.
State one other factor that affects braking distance.
(1 mark)
(v) Applying the brakes of the car causes the temperature of the brakes to
increase.
Explain why.
(2 marks)
In this question you will be assessed on using good English, organising information
clearly and using specialist terms where appropriate.
Describe and explain the factors that affect the stopping distance of
a vehicle.
In your answer you should:
• describe factors that affect stopping distance
• explain how each of the factors you have given affects
stopping distance.
(6 marks)
Quick questions 
1. What is the extension of a spring and how
would you measure it?
2. What happens to an objects motion if the
resultant force is zero?
3. What happens to an objects motion if there
is a non-zero resultant force?
4. What happens to the force of drag as the
speed of an object increases?
Top speed/Terminal velocity
• As you increase speed, drag/air resistance increases
• More streamlined = less drag/air resistance
• Less drag/air resistance = higher speed before the
resultant force is zero
A sky-diver jumps from a plane.
The sky-diver is shown in the
diagram below. Arrows X and Y
show two forces acting on the
sky-diver as he falls.
1. Name the forces X and Y.
(2 marks)
2. Explain why force X acts in an upward direction.
(1 mark)
3. At first forces X and Y are unbalanced. Which of the forces
will be bigger?
(1 mark)
4. How does this unbalanced force affect the sky-diver?
(1 mark)
Sky diver
The graph shows how the vertical velocity of a parachutist changes from the
moment the parachutist jumps from the aircraft until landing on the ground.
Using the idea of forces, explain why the parachutist reaches a terminal velocity
and why opening the parachute reduces the terminal velocity.
Land speed record
This car was built to break the world land speed record.
1. The car accelerates from 0 m/s to a
velocity of 470 m/s.
The car reaches this velocity in 40 seconds.
Calculate the acceleration of the car. Give
the unit.
(4 marks)
2. Describe and explain how the car
reaches its top speed.
(4 marks)
P2 2.6 Stretching and Squashing
Tasks:
1. Write the equation that relates force, spring constant and
extension. Include the units for each part.
2. Write the formula triangle to be able to rearrange it.
3. Draw a diagram to show how the equipment would be set up
to investigate the effect of force on the extension of a spring.
4. Write a quick bullet point method for that experiment
(including how to work out the extension).
5. Describe what Hooke’s Law is.
6. Explain what limit of proportionality is.
7. Answer the summary questions
Sky diver
The graph shows how the vertical velocity of a parachutist changes from the
moment the parachutist jumps from the aircraft until landing on the ground.
Using the idea of forces, explain why the parachutist reaches a terminal velocity
and why opening the parachute reduces the terminal velocity.
Quick Questions 
1. What are the 2 possible units for energy?
2. What is the difference between weight &
mass?
3. What does work done mean?
4. How do you convert kilojoules into joules
and vice versa?
Work done
Work done is the energy transferred by a force to move an object.
Units are Joules, J or kilojoules, kJ.
Past paper question
A chair lift carries two skiers, Greg and Jill, to the top of a ski slope.
Greg weighs 700 N and Jill weighs 500 N.
1. Calculate the work done
to lift Greg and Jill through
a vertical height of 200 m.
Show clearly how you work
out your answer and give
the unit.
(3 marks)
The diagram shows a builder using a plank to help load rubble into a skip.
The builder uses a force of 220 N to push the wheelbarrow up the plank.
Use information from the diagram to calculate the work done to push the
wheelbarrow up the plank to the skip.
Show clearly how you work out your answer.
(2 marks)
Kinetic energy
Ek = ½ x m x
2
v
A car is driven along a straight, snow covered, road. The graph shows how the velocity of the car
changes from the moment the driver sees a very slow moving queue of traffic ahead.
1a) calculate the distance
the car travels while it is
slowing down.
(3 marks)
(b) The car has a mass of
1200 kg.
Calculate the kinetic energy
of the car when it travels at a
speed of 12 m/s.
(3 marks)
The Boat is a theme park ride. The Boat swings backwards and forwards. The
diagrams show the Boat at the top and bottom of its swing.
1. As the Boat swings from its position in A to its position in B, a child on
the ride gains 5070 joules of kinetic energy. The child has a mass of 60
kg and is sitting at the centre.
Calculate the speed of the child as the Boat passes through B. Show
clearly how you work out your final answer.
(4 marks)
The Boat is a theme park ride. The Boat swings backwards and forwards. The
diagrams show the Boat at the top and bottom of its swing.
1. As the Boat swings from its position in A to its position in B, a child on
the ride gains 5070 joules of kinetic energy. The child has a mass of
60 kg and is sitting at the centre.
Calculate the speed of the child as the Boat passes through B. Show
clearly how you work out your final answer.
(4 marks)
For full marks you need to :
1. Rearrange the equation
2. Substitute in the numbers
3. Do the calculation
4. Add units
1. A car is travelling at a speed of 20 m/s when the driver applies the brakes.
The car decelerates at a constant rate and stops. The mass of the car and
driver is 1600 kg.
(i) Calculate the kinetic energy of the car and driver before the brakes are
applied.
(2 marks)
(ii) How much work is done by the braking force to stop the car and driver?
(1 mark)
(iii) The braking force used to stop the car and driver was 8000 N.
Calculate the braking distance of the car.
(2 marks)
(iv) The braking distance of a car depends on the speed of the car and the
braking force applied.
State one other factor that affects braking distance.
(1 mark)
(v) Applying the brakes of the car causes the temperature of the brakes to
increase.
Explain why.
(2 marks)
Gravitational
energy
The diagram shows a diver diving from the end of a diving board.
The height of the diving board above the poolside is 4 m. The mass of the
diver is 50 kg. Gravitational field strength is 10 N/kg.
1 a) Calculate the gain of gravitational potential energy as the diver
climbs from the poolside to the diving board.
(4 marks)
(b) The diver enters the water at a speed of 8 m/s. Calculate the kinetic
energy of the diver as she hits the water.
(4 marks)
(c) As she hits the water her kinetic energy is different from the potential
energy she gained as she climbed to the diving board. Explain why.
(4 marks)
Quick Questions 
1.
2.
3.
4.
5.
What is the unit for momentum?
What is the conservation of momentum?
What does momentum mean?
What is the equation for momentum?
What is the formula triangle for
momentum?
Q1.(a) In any collision, the total momentum of the colliding objects is usually conserved.
However sometimes, momentum is not always conserved. Why?
(1 mark)
b)
(i) Use the information in the diagram to calculate the change in the momentum of the car.
Show clearly how you work out your answer and give the unit.
(3 marks)
(ii) Use the idea of conservation of momentum to calculate the velocity of the van when it
is pushed forward by the collision. Show clearly how you work out your answer.
(3 marks)
A bullet is fired into a block of wood
suspended by a long thread.
The bullet stops in the wooden block.
The impact of the bullet makes the block
swing.
The velocity of the wooden block can be
calculated from the distance it swings.
In one such experiment the block of wood and bullet had a velocity of 2 m/s immediately
after impact. The mass of the bullet was 20 g and the mass of the wooden block 3.980 kg.
(i)
Calculate the momentum of the block of wood and bullet immediately after impact.
(3 marks)
(iii) What was the momentum of the bullet immediately before impact.
(1 mark)
(iv) Calculate the velocity of the bullet before impact.
(3 marks)
(v) Calculate the kinetic energy of the block of wood and bullet immediately
after impact.
(3 marks)
Explosions
Total before = total after
However momentum before =
Why do the teenagers not have the same momentum?
Current Electricity
What are the
units for the
following:
1. Current
2. Potential difference
3. Energy
4. Work done
5. Power
6. Charge
7. Time
8. Resistance
9. Energy transferred
10.Voltage
 To do:
How can many can you remember?
Current
Potential
difference
Series
Parallel
Ammeter
Reading on
ammeter in amps
A
1
A
0.2
A
0.3
2
3
A
4
Definitions & units?
Charge
Current
Potential difference
Resistance
Work done
• Electricity is when electrons move around a circuit and carry energy with
them.
• Each electron has a negative CHARGE.
• Charge is measured in Coulombs (C).
Word
equation
(units)
Symbol
equation
Charge
(in C)
=
current
(in A)
x
time
(in s)
Q
Q = I x t
I
t
LO: Understand how to create electrical circuits
Task
1. What is the current when 20C of charge pass through an
ammeter in 2minutes?
2. A battery can produce 20A of current. How much charge
does it discharge in 30s?
3. Another battery can produce a charge of 30A. How long
will this battery be running before it has discharge the
same amount of charge as the battery in Q2?
4. A car engine requires a battery that can produce a
current of 40A to start. A mechanic places a battery that
can discharge 100C in 30s into a car. Will this battery be
good enough to start the car? Why?
5. For the question above, how much charge would the
battery have to discharge in 30s to start the engine?
• The work done or energy transferred by each coulomb of charge
• Sometimes called voltage
• Potential difference is measured in Volts (V).
Word
equation
(units)
Symbol
equation
Potential
difference
(in V)
=
V = W
Q
Work done (in J)
Charge (in C)
W
V
Q
The circuit below is switched on for 2 minutes. During this time, 72
coulombs of charge pass through the lamp.
Use the correct equation to calculate the energy transformed by the lamp
while the circuit is switched on.
(3 marks)
• Why do electrons experience resistance in a wire?
• Resistance is measured in Ohms (Ω).
• Total resistance of components in series is equal to the sum of resistance of
each component
Word
equation
(units)
Symbol
equation
Resistance
(in Ω)
R = V
I
=
Potential difference (in V)
Current (in A)
V
R
I
The resistance of a 24 W, 12 V filament lamp depends on the
current flowing through the lamp. For currents up to 0.8 A, the
resistance has a constant value of 2.5 Ω.
Use the correct equation to calculate the potential difference
across the lamp when a current of 0.8 A flows through the
lamp.
(3 marks)
When correctly connected to a 9 volt battery a wire has a
current of 0.30 amperes flowing through it.
Use the correct equation to calculate the resistance of the
wire. Show clearly how you work out your answer and give
the unit.
(3 marks)
Ohm’s Law
Ohm’s Law states that the
current through a resistor is
proportional to the potential
difference provided the
temperature is constant
Current-potential difference graphs
Which one of the components A, B or C could be a 3 volt filament
lamp? Explain the reason for your choice.
(3 marks)
Mark scheme
• C
• resistance increases
negated by wrong statement e.g. current goes down
• as the lamp gets hot
accept as current (through lamp) or voltage (across lamp) increases
Current-potential difference graphs
Thermistors & LDRs
NEGATIVE RELATIONSHIPS!!!
Increase in light =decrease in resistance
Increase in temperature = decrease in resistance
Mains Electricity
1. Label part A, B, wire X , wire Y and wire Z. What colour are
the three wires?
2. What do each of the wires do?
3. Give 4 common mistakes that might occur when wiring a
plug.
AC/DC
1. Describe the difference between an alternating current (a.c.) and a direct
current (d.c.).
2. Calculate the value of the largest peak potential difference.
The oscilloscope is now connected across a 3 V battery. The battery
supplies direct current (d.c.). The settings on the oscilloscope are not
changed.
On the diagram below draw the trace you would see on the
oscilloscope screen.
Q3. The diagram shows two oscilloscope traces, A and B.
Trace A shows how the potential difference between the live and neutral terminals
of an electricity supply changes with time.
a) Describe how the potential of
the live terminal varies with
respect to the neutral terminal
of the electricity supply.
b) Each horizontal division on the
oscilloscope represents 0.005 s.
(i) What is the period of this
electricity supply?
(ii) Calculate the frequency of
the supply.
• The power of an appliance is the energy (in Joules) it transfers in 1 second
• The current is the flow of charge (electrons) each second.
• The potential difference across a component is the energy transferred by
each coulomb of charge.
Word
equation
Power
(units)
(in W)
Symbol
equation
=
current
(in A)
x
potential
difference
(in V)
P
P = I x V
I
V
Power = current x potential difference
1150 W
(3)
Power and fuses
1. The fuse inside a plug is a safety device.
Explain what happens when too much current passes through a
fuse.
Appliance
Power rating
(W)
Voltage (V)
Toaster
720
230
Fire
2000
230
Hairdryer
300
230
Hoover
1000
230
Computer
100
230
Stereo
80
230
Current
needed (A)
Fuse needed
(3, 5 or 13A)
RCCBs
1. What happens, as the cable is cut, to cause the RCCB to switch
the circuit off?
2. A circuit can also be switched off by the action of a fuse.
Give two advantages of using a RCCB to switch off a circuit rather
than a fuse.
• The amount of energy that flows in a circuit depends on
1.
2.
the amount of charge carried by the electrons
the voltage pushing the charge around
• The energy from the battery is equal to the sum of the energy transferred
to all the components in a circuit.
Word
equation
Energy =
(in J)
potential
difference
(in V)
x
charge
(in C)
E
Symbol
equation
E = V x Q
V
Q
b) The 230 volt mains electricity supply causes a current of 11
amps to flow through the cable.
(i) Calculate the amount of charge that flows through the cable
when the cable is switched on for 2 hours and give the unit.
Use the correct equation from the Physics Equations Sheet.
(3)
(ii) Calculate the energy transferred from the cable to the soil in
2 hours.
Use the correct equation from the Physics Equations Sheet.
(3)
Charge = energy / potential difference
210 C
Current = charge / time
0.7 A
1. Most elements have some isotopes which are radioactive.
(a) What is meant by the terms:
(i) isotopes
(ii) radioactive?
(2 marks)
2. Draw a line from each
type of radiation to the
correct description.
Draw only 3 lines
(3 marks)
(a) The chart gives the number of protons and neutrons within the nuclei of 7 different
atoms, A – G.
Which of these atoms are isotopes of the same element?
Give a reason for your answer.
(2 marks)
1. Describe the structure of alpha particles.
(2 marks)
2. What are beta particles?
(1 mark)
3. Describe how beta radiation is produced by a
radioactive isotope.
(1 mark)
In the early part of the 20th century, scientists used the ‘plum pudding’ model to
explain the structure of the atom.
Following work by Rutherford and Marsden, a new model of the atom, called the
‘nuclear’ model, was suggested.
Describe the differences between the two models of the atom.
(4 marks)
The diagram shows the paths, A, B and C, of three alpha particles. The total number
of alpha particles deflected through each angle is also given.
b) Using the nuclear model of the atom, explain the three paths, A, B and C.
(3 marks)
Alpha
Structure
Charge
Ionisation
effect
Deflection in
magnetic
field?
Deflection in
electric field?
Beta
Gamma
Radiation equations
Alpha () – an atom decays into a new atom and emits an alpha
particle (2 protons and 2 neutrons – the nucleus of a helium atom)
Beta () – an atom decays into a new atom by changing a
neutron into a proton and electron. The electron is called a beta
particle.
Gamma – after  or  decay surplus energy is sometimes
emitted. This is called gamma radiation and has a very high
frequency with short wavelength. The atom is not changed.
1. Radium-226 is a radioactive isotope that decays into radon gas by emitting alpha particles. The
decay can be represented by the equation below.
(2)
Complete the equation by writing the correct number in each of the boxes.
(2 marks)
2. An atom of iodine-131 decays into an atom of xenon (Xe) by emitting a beta particle. The decay
of iodine-131 can be represented by the equation below.
Complete the equation by writing the correct number in each of the two
boxes.
(2 marks)