last minute exam revision

Question 1

what is current?

Answer 1

the electric charge transferred per unit time

Question 2

give an example of a d.c supply

Answer 2

a battery

Question 3

mains electricity?

Answer 3

50Hz
230 v
a.c

Question 4

what is mass?

Answer 4

The amount of matter and object takes up

Question 5

what is gravitational field strength?

Answer 5

The force due to gravity per unit mass

Question 6

satellites have a constant vertical acceleration

Question 7

force is a vector

Question 8

Electrostatic charge has many applications in everyday life.
Using your knowledge of physics, discuss some of these applications

Answer 8

Cling film to keep food fresh
Static dusters for cleaning
Printers/photocopiers where charge attracts ink to the paper.

Question 9

what do field lines show and where are they the strongest?

Answer 9

field lines in an electric field show the direction a positive charge placed in a field would make.
Field is strongest where field lines are closest together

Question 10

order of particles in increasing size?
helium nucleus, electron, proton?

Answer 10

electron, proton, helium nucleus

Question 11

how is something connected?

Answer 11

series or parallel

Question 12

why is the …. not as fast as calculated in part …?

Answer 12

because energy is lost as heat due to friction

Question 13

if given a forward force and a frictional force take away to get the force

Question 14

who should you use a space based telescope instead of a ground based telescope?

Answer 14

no light pollution
can use it during the day

Question 15

time for equivalent dose rate is just in hours/mins

Question 16

what is acceleration?

Answer 16

acceleration is the change in velocity, per unit time

Question 17

projectiles

Answer 17

A projectile is an object in unpowered flight. Ignoring air resistance there is only one force acting on a projectile - weight.

A projectile has:
A constant horizontal velocity
A constant vertical acceleration

parabolic flight path

Question 18

projectiles 2

Answer 18

ONLY AIR RESISTANCE affects the time and object takes to fall, NOT MASS
a larger horizontal velocity will increase the horizontal range of the projectile, but doesn’t affect the time taken to fall.

Question 19

As altitude increases, what happens to the acceleration of a rocket?

Answer 19

Acceleration increases because it’s weight decreases because fuel is burned & parts are ejected

Question 20

As altitude increases what happens to the weight of a rocket?

Answer 20

As altitude increases weight decreases because gravitational field strength decreases as altitude increases and mass decreased because fuel is burned
w = mg

Question 21

when doing resultant vectors do Pythagoras and it’s just the number WITH m UNIT
then when you do trigonometry ADD A DIRECTION

direction might be right, left, forwards, backwards
LOOK AT THE LITTLE ARROW AND SEE IF IT SAYS NORTH OR FORWARDS

Question 22

what is weight?

Answer 22

The downwards pull on an object due to gravity