There are two parts to 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.

Stopping distance = Thinking Distance + Braking DistanceStopping distance = Thinking Distance + Braking Distance

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

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

3-4 As above but friction is linked to energy loss

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 resistance5-6 Detailed explanation of energy

transfers that take placeAnswer 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 throughoutPossible extra detail includes:Explanation of GPE and KE equations linked to answerDetailed explanation of cause of friction eg air resistance due to collisions between air molecules/ball