distance time graphs
1. gradient = speed
2. flat sections where its stopped
3. steeper the graph, faster its going.
4. downhill sections - coming back to starting point.
5. curves represent acceleration
6. steepening curve - speeding up
7. leveling off curve - slowing down
velocity time graphs
1. gradient = acceleration
2. flat sections - steady speed
3. steeper the graph greater acceleration/deceleration
4. uphill - acceleration
5. downhill - deceleration
6. area under any section = to distance travelled in that time interval
7. curve - changing acceleration
moving objects normally experience friction
a) friction between solid surfaces which are gripping
b) friction between solid surfaces which are sliding past each other
c) resistance of "drag" from fluids - moving object has to force through particles
G.P.E is Height energy
- energy stored in an object when you raise it to a height against the force of gravity,
- change in g.p.e = weight (N) x change in height (m)
- when something falls g.p.e is converted into k.e the further is falls the faster is goes.
- kinetic energy gained = potential energy lost
when two insulating objects are rubbed together, electrons are scraped off one and dumped onto the other.
this leaves a positive charge on one and a negative charge on the other.
which way electrons are transferred depends on the materials
electrically charger objects attract small objects placed near them
note: only electrons move never the positive charges
liked charges repel - opposite charges attract