There are two parts to stopping distance:
•Thinking distance
•Braking distance
Stopping distance = Thinking Distance + Braking Distance
Both of these can be increased by different factors.
Explain in detail how road conditions, speed and
alcohol can affect road safety.
The quality of written communication will be assessed in
your answer to this question.
Explain the energy changes that take
place as a ball is released along the
following track.
Marks
Answer
Detail
1-2
Basic description of energy changes
that take place as ball moves down the
track.
Mention of friction but no clearly
linked to energy loss
As above but friction is linked to
energy loss


3-4
5-6
Detailed explanation of energy
transfers that take place


Ball gains GPE as it is moved up the ramp
As it moves down the ramp GPE is converted to KE
(speeds up)
“Friction slows the ball down” or similar
As the ball moves some of its KE is lost due to friction
so it does not regain all the GPE it had on the other
side of the ramp.
 Possible mention of KE lost as heat to surroundings
 Possible mention of friction between ball and ramp
and/or air resistance
Answer should include (for full 6):
 Detailed description of the cause of friction (ball/track
& air resistance)
 Idea that energy is conserved
 Few (if any) errors in SPAG and correct use of technical
terms throughout
Possible extra detail includes:
 Explanation of GPE and KE equations linked to answer
 Detailed explanation of cause of friction eg air
resistance due to collisions between air molecules/ball