AQA GCSE Physics (8463), Higher tier · Forces › Forces and motion › Forces and braking
Practise Reaction time. 11 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Cover the answers and test yourself. The app has these as flashcards that come back just before you'd forget them.
Give two factors that can increase a driver’s reaction time.
Any two of: tiredness, alcohol, drugs, distractions.
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
(a) Which of these is a typical reaction time for a driver? Tick (✓) one box.[1]
0.02 s
0.5 s
2.5 s
5.0 s
(b) Give two factors that can increase a driver’s reaction time.[2]
(c) A driver has a reaction time of 0.60 s and is travelling at 15 m/s. Calculate the thinking distance. Use the equation: distance = speed × time[2]
Show the answer and mark scheme
(a)Answer: 0.5 s
(b)Answer: Any two of: tiredness, alcohol, drugs, distractions.
tiredness
drinking alcohol
taking (some) drugs
distractions, e.g. using a mobile phone
(c)Answer: 9.0 m
s = 15 × 0.60
9.0 (m)
Question 2Medium5 marks
A student carries out the ruler-drop test to measure their reaction time.
(a) Explain why the student should repeat the test several times and calculate a mean, rather than relying on a single reading.[2]
(b) The student’s five results are 0.18 s, 0.21 s, 0.19 s, 0.55 s and 0.20 s. Identify the anomalous result.[1]
(c) Calculate the mean of the remaining results.[2]
Show the answer and mark scheme
(a)Answer: A single reading may be untypical or anomalous; a mean of repeats reduces the effect of random variation.
a single reading could be affected by random variation (for example a lapse in concentration), so it may not be typical / could be anomalous
repeating and calculating a mean reduces the effect of random variation, giving a more reliable value
(b)Answer: 0.55 s.
0.55 s
(c)Answer: 0.20 s (0.195 s) s
(0.18 + 0.21 + 0.19 + 0.20) ÷ 4
0.20 (s) (0.195)
Question 3Hard7 marks
Some students think that talking on a hands-free phone increases a person’s reaction time.
(a) Plan an investigation, using the ruler-drop test, to find out whether talking on a hands-free phone affects a person’s reaction time.[6]
(b) Suggest why person B should not be able to see person A’s hand before the ruler is dropped.[1]
Show the answer and mark scheme
(a)
person A holds a metre rule vertically with the zero mark level with the top of person B’s thumb, with B’s thumb and finger either side of (not touching) the ruler
person B rests their forearm on the edge of a table so that the hand is in a fixed position
person A drops the ruler without warning and person B catches it as quickly as possible
record the distance the ruler falls, read at the top of the thumb
repeat several times (e.g. 10) and calculate a mean, ignoring anomalies
repeat the whole test while person B is talking on a hands-free phone
control variables: same catcher, same hand, same ruler, same starting position, same person dropping
convert distances to reaction times using a conversion table (or t = √(2d ÷ g))
compare the mean reaction times with and without the phone call
Marked with levels of response: the full level descriptors are in the app.
(b)Answer: So B reacts to the ruler moving rather than anticipating the drop.
so that person B reacts to the ruler moving and cannot anticipate the drop