physics (year 7)

what is an independant variable

the one you can change

what is a dependant variable

the one you measure

what is a control variable

the one thats stays the same

what is the symbol equation for speed = distance/time and their units

s = d/t

s = m/s

d = m

t = s

m - cm

x 100

cm - mm

x 10

m - mm

x 1000

what are the steps to the practical in motion of everyday objects

1. set out a ramp by placing 5 books beneath a wooden plank. then place a light gate at the bottom

2. put a card on the object you are wanting to measure the speed of and gently put in on a ramp and let it role down the bottom

3. once the object has passed the light gate read the speed given. repeat this 3 times to create an average

4. then repeat the whole method again for the other objects you want to measure

what is current

current is the rate of flow of charge

what is the symbol equation of charge = current x time and its units

Q = I x t

Q = C coulombs

I = A amps

t = s

why is current conserved at a junction

it is conserved at a junction because the current needs to be split to take both parts but comes back together when paths rejoin

advantages of parallel circuits

1. components can be switched on/off independently

2. bulbs maintain similar brightness

3. if one component breaks, current can still flow through other parts of a circuit

advantages of a series circuit

1. uses less power

2. fewer wires = cheaper + easier to assemble

what is the symbol equation for density = mass/volume and its units

p = m/v

p = kg/m³ or g/cm³

m = kg or g

v = m³ or cm³

how to convert m³ into cm³

x 1000000 (6 0s)

what is a universe

a large collection of billions of galaxies

what is a galaxy

a large collection of billions of stars

where is our solar system

in the milkyway galaxy

a universe is bigger then…

a galaxy