AQA GCSE PHYSICS 8463 LATEST EXAM WITH
200+ QUESTIONS AND WELL VERIFIED
ANSWERS || ALREADY GRADED A+ |
GUARANTEED PASS | LATE ST VERSION |
Why are cars designed with safety features? - ANSWER-- to slow people down over a long time when they have a car crash
- the longer it takes for a change in momentum, the smaller the force
What do breaks do? - ANSWER-reduce the kinetic energy of the car by transferring it into heat energy
What is the difference between standard brakes and regenerative brakes? - ANSWER-standard brakes= kinetic energy into heat energy regenerative brakes put motor running backwards- electricity generated and stored
How are cars designed to convert kinetic energy safely in a crash? - ANSWER-- crumple zones at front and back of car
- seat belts
- air bags
- side impact bars
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What do crumple zones do? - ANSWER-- crumple upon impact
- cars kinetic energy is converted into other forms of energy by the car body as it
- the increase the impact time
- decrease the force produced by the change in momentum
changes shape
How do you work out voltage of a circuit with cells? - ANSWER-add voltage of each cell
What is a parallel circuit? - ANSWER-- each component is separately connected to the power source
- if you remove or disconnect one of them, it will hardly affect the others at all
What is the P.D like in a parallel circuit? - ANSWER-- same across all components in parallel
V1 = V2 = V3
- this means identical bulbs connected in parallel will all have the same brightness
What is the current like in a parallel circuit - ANSWER-- the total current flowing around the circuit is equal to the total of all the currents through the separate components
A= A1 + A2 + A3
- if two identical components are connected in parallel then the same current will
flow through each component 2 / 4
Ammeters are always... - ANSWER-connected in series, even in a parallel circuit
Voltmeters are always... - ANSWER-connected in parallel with a component, even in a series circuit
How alpha, beta and gamma radiation are deflected by electric and magnetic fields
- ANSWER-- alpha particles have positive charge, beta particles have a negative
charge
- when travelling through a magnetic or field, alpha and beta particles will be
deflected
- they're deflected in opposite directions due to their opposite charge
- alpha particles have a larger charge than beta particles, and feel a greater force in
magnetic and electric fields. but they're deflected less because they have a much greater mass
- gamma radiation is an electromagnetic wave and has no charge so it doesn't get
deflected by electric or magnetic fields
What is a half-life? - ANSWER-the average time it takes for the number of nuclei in a radioactive isotope sample to halve
A short half-life means... - ANSWER-the activity falls quickly, because lots of the nuclei decay quickly
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A long half-life means. - ANSWER-the activity falls more slowly because most of the nuclei don't decay for a long time, they just sit there, basically unstable
Why do radioactive isotopes have a half-life? - ANSWER-decay as activity decreases, less radiation, different per substance, how many nuclei decay and when
Do half-life questions step by step. - ANSWER-INITIAL count (÷2) after ONE half-life (÷2) after TWO half-lives (÷2) after THREE half-lives
The activity of a radioisotope is 640 cpm (counts per minute). two hours later it has fallen to 80 cpm. find the half-life of the sample. - ANSWER-INITIAL count= 640 after ONE half-life = 320 after TWO half-lives = 160 after THREE half-lives = 80
it takes three half-lives for the activity to fall from 640-80. two hours represents three half-lives, so the half-life is 120 ÷ 3 = 40 minutes
How to find the half-life of a sample using a graph? - ANSWER-find the time interval on the bottom axis corresponding to a halving of the activity on the vertical axis
What are the uses of radiation? - ANSWER-- smoke detectors
- tracers in medicine
- radiotherapy (cancer)
- sterilization of food and surgical instruments
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