P2 - Physics - Reigate School

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P2 Exam Date: Thursday 23rd May 2013

P2 - Physics

Question Pack

KEY WORDS: velocity

acceleration deceleration

speed

ASSESSMENT:

P2 REVISION – PART 1 – MOTION

Distance-Time Graphs The gradient of the line on a distance-time graph represents _________. The ______________ the gradient, the greater the speed. If an object is stationary, the line on a distance-time graph is ______________. If an object is moving at a constant speed, the line on a distance-time graph is a straight line that slopes _____________.

Velocity & Acceleration

If the value calculated for acceleration is negative, the body is decelerating – slowing down. A deceleration is the same as a negative acceleration.

Velocity-Time Graphs

The gradient of the line on a velocity-time graph represents ______________. The steeper the ____________, the greater the acceleration. What does a horizontal line show on a velocity-time graph? What area on a velocity-time graph shows the distance?

Using Graphs

Calculate the gradient of the line on a distance-time graph to give you the speed of an object.

Calculate the gradient of the line on a velocity-time graph to give you the acceleration of an object.

Match the graph to the description of motion:

KEY WORDS:

distance-time graphs gradient speed

velocity acceleration

velocity-time graphs

ASSESSMENT:

P2 REVISION – PART 1 – MOTION

KEY WORDS: Force

Newton mass

ASSESSMENT:

Forces Between Objects

P2 REVISION – PART 2 – FORCES

Stopping distance

Distance travelled during the thinking distance, plus the distance it travels under the braking distance

Thinking distance

Is increased if the driver is tired or under the influence of _____________ or __________.

Braking distance

Can be increased by: Poorly maintained roads Bad weather conditions. Condition of the car: eg: Worn ____________ Worn ____________

Forces are measured in newtons, N. What is the rule with regard to forces?

Resultant Force

The resultant force is a single force that has the same effect as all the forces acting on an object. If an object is accelerating there must be a resultant force acting on it. If an object is accelerating what 3 things can it be doing?

Force & Acceleration What always causes an acceleration? The bigger the resultant force on an object, the greater its ___________________.

F = m x a

F is the resultant force in newtons, N. m is the mass in kilograms, kg a is the acceleration in m/s²

Acceleration is a change in velocity. An object can accelerate by changing its ________________ even if it is going at a ______________ ____________. Therefore a ___________________ ______________ is needed to make an object change __________________.

On The Road If a vehicle is travelling at a steady speed, the resultant force on it is __________. The driving forces are equal and opposite to the frictional forces.

Reaction time depends on the ____________. Braking distance depends on the ___________, ___________ _____________ and the condition of the vehicle.

KEY WORDS: force

resultant force stopping distance thinking distance braking distance

weight mass

gravitation field

strength drag force

terminal velocity proportionality Hooke’s law

ASSESSMENT:

What is the definition of a force? What are balanced forces and when do they occur? What are unbalanced forces and when do they occur?

Calculate the resultant force:

Using the formula F=ma, fill in the table

a b c d e

Force (Newtons, N) 200 840 5000

Mass (kilograms, kg) 20 7.0 0.40

Acceleration (meters/second squared, m/s2) 0.80 5.0 6.0 0.20

What is stopping distance, and what are the two parts that make up a car’s stopping distance? What factors affect stopping distance?

What do we do to prevent speeding in this country?

What is terminal velocity? What is Hooke’s law?


KEY WORDS: gravitational drag force

terminal velocity weight elastic

proportionality

ASSESSMENT:


Falling Objects

The force of gravity is called ___________ An object acted on only by gravity will accelerate at about ___________. F = m x a Where: F is the resultant force in newtons, N. m is the mass in kilograms, kg a is the acceleration in m/s² Becomes: W = m x g Where: W is the weight in newtons, N m is the mass in kilograms, kg g is the acceleration due to gravity in m/s² If an object falls through a fluid the fluid exerts a __________ force on the object. Faster the object falls, the bigger the drag force becomes until it becomes equal to the weight of the object. Resultant force will then be ___________. This is called ________________ _______________. DON’T FORGET: Mass is the amount of matter in an object. Weight is the force of gravity acting on it.

Stretching & Squashing What does elastic mean? The extension of a spring is DIRECTLY PROPORTIONAL to the force applied to it, provided the limit of proportionality is not exceeded. How do we know that it is directly proportional? Extension is the difference between the length of the spring and its ____________ _________. Hooke’s Law Equation: F = k x e Where F is the force applied in newtons, N k is the spring constant of the spring in newtons per metre, N/m e is the extension in metres, m What is the spring constant of a spring?

Force & Speed Issues

Reduces the speed of a vehicle reduces the amount of what? What is this called? Reducing air resistance, making a vehicle more _________________ also improves fuel economy. Speed cameras are used to discourage motorists from doing what? In pairs they can be used to calculate __________________ speed. What happens if you are caught speeding? When does skidding happen? What happens when you skid? _________ ___________ surfaces are used to reduce or prevent skidding. How do these surface work? Where are they used?

KEY WORDS: work

friction kinetic energy

elastic potential energy

ASSESSMENT:

P2 REVISION – PART 3 – WORK, ENERGY & MOMENTUM

Energy & Work Work is done on an object when a force makes the object move. Energy transferred = work _______ What is the unit for both work and energy? W = F x d Where: W is the work done in joules, J F is the force in newtons, N d is the distance moved in the direction of the force in metres, m Work done to overcome _____________ is transferred as energy that heats the objects that rub together and the surroundings.

Gravitational Potential Energy Kinetic Energy

Explosions

Momentum has both size and direction. One direction must be ________________, therefore momentum in the opposite direction is negative. In an explosion the objects will move apart with _______________ and ______________________ momentum. One being positive the other ______________. So the total momentum after the explosion is ____________.

The object will move apart with different speeds if they have _____________ _______________.

KEY WORDS:

transfer work done

gravitational potential energy elastic potential energy

momentum conservation of momentum

ASSESSMENT:

What is work done? What is the equation for work done? How does friction affect work done?

What features do we add to cars to make them safe?

What is momentum? Complete the question below using this equation momentum (kg m/s) = mass (kg) X velocity (m/s) If a sprinter with a mass of 50kg runs at a velocity of 10m/s what is their momentum? A 0.5 kg trolley is pushed at a velocity of 1.2 m/s into a stationary trolley with a mass of 1.5 kg. The two trolleys stick to each other after the impact. Calculate: The momentum of the 0.5 kg trolley before the collision The velocity of the two trolleys straight after the impact

What is conservation of momentum and how do you calculate it?


KEY WORDS: impact time

crumple zone

ASSESSMENT:

Impact Forces

When vehicles collide the force of the impact depends on what 3 things? When two vehicles collide they exert ______________ and __________________ forces on each other, also their total _______________________ is unchanged. What is impact time?

Car Safety

Cars today have several different safety features built into them, to reduce the forces on the occupants of the car in a collision. How do side impact bars, seat belts, air bags and crumple zones help with safety?

Questions What can we use to find out the speed of a car before an impact? What is the unit of momentum? Where do you have crumple zones on a car and why?


KEY WORDS: insulating electron attract repel

resistance series

ASSESSMENT:

P2 REVISION – PART 4 – CURRENT ELECTRICITY

Electric symbols Electrical Charges If you rub two electrically insulating materials are rubbed together, _______________ are rubbed off one material and deposited on the other. Objects that have opposite electric charges _________ each other, if they have the same electric charge they _________.

Resistance

Current is measured with an ammeter. Where are ammeters placed in relation to the component? What is the unit of current? The potential difference(pd) across a component is measured with a voltmeter. These are always placed in parallel with the component. What is the unit of potential difference?

V is ? W is ? Q is ? Don’t forget units!

R is ? V is ? I is ? Don’t forget units!

Ohm’s law: states that the current through a resistor at constant temperature is directly proportional to the potential difference across the resistor.

Electric Circuits

I is the current in amperes, A Q is the charge in coulombs, C t is the time in seconds, s.

Every component has an agreed circuit symbol. Make sure you can recognise and draw them!

Link the component to the correct graph

Label these circuit components:

KEY WORDS: static electricity

protons neutrons

ion electric current

electrons coulombs (C)

series

potential difference volts (V) parallel

resistance ohmic conductor

ASSESSMENT:

What is static electricity? What happens when you rub a polythene rod with a dry cloth? What happens when you rub a perspex rod with a dry cloth?

You can use diagrams to help.

What is resistance? What is the equation for resistance? What is the rule for resistance in a series circuit? What is the rule for resistance in a parallel circuit?


KEY WORDS: diode

filament bulb resistor

thermistor

ASSESSMENT:

Current-Potential Difference Graphs

A current-potential difference graph for a resistor.

A current-potential difference graph for a filament bulb, line is a curve so the current is not directly proportional to the __________________ ___________________.

The current in a diode flows in one direction only, in the reverse direction the diode has a very high resistance so the current will be what?

Thermistor: Resistance _______________ if its temperature increases. LDR: resistance decreases if the light intensity on it ___________.

Series Circuits

How are the components connected in a series circuit? What happens if there is a break in the circuit? Is the current the same or different through each component? If you add together the potential difference what does it give you?

The resistance of the individual components add up to give the total resistance of the circuit.

Parallel Circuits

How are the components connected in a series circuit? What happens if there is a break in the circuit? Is the pd across each component the same or different? The bigger the resistance of a component, the ______________ the current through it. Use this equation to work out the

current through a component in a parallel circuit.


KEY WORDS: current

frequency oscilloscope

circuit breaker

ASSESSMENT:

P2 REVISION – PART 5 – MAINS ELECTRICITY Alternating Current

Direct current is supplied by cells and batteries and passes round the circuit in one direction. Alternating current is from the mains, how does it travel? Frequency of am ac supply can be worked out from an oscilliscope trace using the equation:

Cables & Plugs

Why are the pins of a plug made of brass? What does the earth wire earth? Why are some cables thicker than others?

Fuses How does a fuse work? Where is a fuse fitted in a circuit? How does a circuit breaker work?

Electrical Power & Potential Difference

Power can be calculated using the above equation.

Using the current and the pd and the equation above enables us to calculate the power of an appliance. To work out the correct rating in amperes for a fuse rearrange the above equation, what would the equation now be?

Electrical Energy & Charge

An electric current is the flow of what? What is the equation that relates to charge, current and time? When charge flows through a resistor, what makes it hot?

What can you use this equation for?

Electrical Issues

Electrical faults are dangerous what two things can they cause? Why must you check cables, plugs and sockets for damage regularly? What must you not touch with wet hands? Why are filament bulbs very inefficient?

In a standard 3-pin plug what is...? X: Y: Z: How do the materials and design of the following plug parts improve their safety? case fuse pins How are electrical cables designed to be safe?

KEY WORDS:

direct current alternating

current frequency

live/neutral/ earth wire

Oscilloscope Y-gate control

time base control socket plugs

cable three-pin plug circuit breaker

residual current circuit breaker

(RCCB)

ASSESSMENT:

What is the difference between direct current and alternating current? Why do we use alternating current for mains electricity? How do we measure alternating current?

Z

What is a fuse and how does it work? What is a circuit breaker and how does it work?

Electrical energy and charge Work through these questions: Calculate the charge flow when the current is 8A for 80s.

Q = I X t

Calculate the energy transferred in a component when the charge passing through it is 30C and the potential difference is 20V

Energy transferred = volts X coulombs

P2 REVISION – PART 5 – MAINS ELECTRICITY

KEY WORDS: ion

isotope nucleus proton

electron radiation

ASSESSMENT:

P2 REVISION – PART 6 – RADIOACTIVITY

Observing Nuclear Radiation

An atom has a small central _________________, which contains the ____________ and _________________, this is then surrounded by_______________________. The nuclei of radioactive substances are unstable, to become stable they go through a process called radioactive decay. The 3 types of radiation emitted are: Where does background radiation come from? Remember: Radioactive decay is random we cannot predict or influence when it happens!

Discovery of the Nucleus

Scientists originally called the model of the atom the ‘plum pudding’. Rutherford, Geiger and Marsden then did an alpha particle scattering experiment, they fired alpha particles at thin gold foil. Most passed straight through the foil, what does this mean?

Some of the alpha particles are deflected through small angles, what does this mean? A few rebound through large angles what does this mean?

Nuclear Reactions Change In The Nucleus Particle Emitted

α decay

β decay

Relative Mass Relative Charge

proton

neutron

electron

What is an atom called if it loses or gains electrons? What is an isotope? When a nucleus emits an alpha particle the atomic number goes down by _____ and the mass number goes down by ___. When a nucleus emits a beta particle the atomic number goes up by ___ and the mass number stays the same. Is there any change when a nuclear emits gamma radiation?

KEY WORDS: ionisation half-life tracer

radioactive dating

ASSESSMENT:

Half-Life

What is the half-life of a radioactive isotope? The number of atoms of a radioactive isotope and the activity both decrease by __________ every half life.

Radioactivity At Work

Where Used And Length Of Half-life

Alpha

Beta

Tracers in medicine. Half-life of a few hours so that patient is not exposed to unnecessary radioactivity.

Radioactive Dating: What is this used for? What do we need to do it?

Alpha, Beta & Gamma Radiation

Remember what stops each type of radiation.

Deflected by? How ionising?

Alpha electric & magnetic fields

Beta not as ionising as alpha particles

Gamma deflected by neither electric or magnetic fields.

Ionisation is when nuclear radiation travels through a material, colliding with the atoms within it. This then knocks electrons off, creating ions.


ASSESSMENT:

How did each of these scientists contribute to our understanding of radiation? Henri Becquerel: Marie Curie: Ernest Rutherford:

What is radiation? What causes background radiation?

Explain what half-life is: Fill in this table assuming there is a 10% decay every hour:

Time from start (hours) 0 1 2 3 4 5 6

No. of unstable atoms 1000 900 477

No, of unstable atoms that decay in the next

hour 100 90 48

Give 3 uses of radioactivity, and a brief description of how they work:

Properties of radiation:

Penetrating Power

Deflection By Magnetic Field

Deflection By Electric Field


KEY WORDS: radioactivity

alpha beta

gamma

KEY WORDS: star

nuclear fusion chain reaction nuclear fission

ASSESSMENT:

P1 REVISION – PART 7 – ENERGY FROM THE NUCLEUS

Nuclear Fission

Nuclear fission is the splitting of a nucleus into two approximately equal fragments and the release of two or three neutrons. What two fissionable isotopes are most commonly used in nuclear reactors? When does a chain reaction occur?

Nuclear Fusion

Nuclear fusion is the process of forcing two nuclei close enough together so they form a single larger nucleus. What is released when this happens? Where does nuclear fusion take place?

Nuclear Issues

What is a major source of background radiation? Name two other sources of background radiation. How is nuclear waste stored? Why must it be stored securely?

The Early Universe

How and when do many scientists think the universe was created? What pulled the gas and dust together to form stars? What are very large groups of stars called?

KEY WORDS: pro star

supernova neutron star

ASSESSMENT:

Life History Of A Star

Protostar: Gas and dust cloud in space that can go on to form a star. Low mass star: Protostar main sequence star red giant white dwarf Black dwarf High mass star: Protostar main sequence star red supergiant Supernova black hole if sufficient mass. What will the sun eventually become? What is a supernova?

How The Chemical Elements Formed

Gas, rocks and dust

The sun forms at the centre of a spinning cloud of dust, gas and rock.

The sun’s energy evaporates ice and drives gas away from

the inner solar system, leaving rocks behind.

The rocky planets form near the Sun and the gas giant planets form further away. The minor planet Pluto orbits the

Sun beyond the giant planets.

Elements as heavy as iron are formed inside stars as a result of nuclear _______________. Elements heavier than iron are formed in supernovas, along with lighter elements. What were the sun and the rest of the solar system formed from?


KEY WORDS: nuclear fission chain reaction

reactor control rods

coolant nuclear fusion

protostar neutron star

main sequence

stars red giant

white dwarf black dwarf supergiant supernova black hole

ASSESSMENT:

Explain nuclear fission (use diagrams):

Explain nuclear fusion (use diagrams):

What are some of the issues linked with nuclear energy?

What was the early universe like?

Explain the life cycle of a star:

How are chemical elements formed?


P2 - Physics - Reigate School

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