One to two mark questions will start with command words such as 'describe' or 'explain'. Some command words are easy to understand such as:
The command words 'describe' and 'explain' can be confusing. If you are asked to describe a graph, you will be expected to write about its overall shape, whether it is linear or curved, the slope of gradients etc. If you are asked to explain why a pattern or trend is seen in a graph, you will be expected to use your science knowledge, not just say what you see (which is a description), eg 'The graph shows a steep linear increase for the first three hours because…'.
'Explain how' and 'why' questions often have the word 'because' in their answer. 'Describe' questions don't.
The number of marks per question part is given in this form '[2 marks]'. It is essential that you give two different answers if a question is worth two marks. Sometimes you can gain a second mark by giving the units in a calculation or stating specific data points, eg the speed of the object decreased by 8 m/s.
This page contains AQA material which is reproduced by permission of AQA.
A car makes an emergency stop.
The figure below shows the thinking distance and braking distance of the car:
What is the stopping distance? [1 mark]
The total thinking distance and braking distance combined = 74 m 
Stopping distances are made up of a thinking distance and a braking distance and could be thought of as a simple equation:
Stopping distance = thinking distance + braking distance
An actor has a mass of 70 kg.
Gravitational field strength = 9.8 N/kg
Use the following equation to calculate the weight of the actor:
Weight = mass × gravitational field strength
Give your answer to two significant figures. [2 marks]
weight = mass × gravitational field strength
= 70 × 9.8 = 686 N 
= 690 N to 2 sf 
Always show all stages of a calculation.
A swimmer dives off a boat.
What two factors determine the momentum of the swimmer? [2 marks]
mass  and velocity 
The equation for momentum is momentum = mass × velocity
Therefore the momentum of an object will be different if either mass or velocity change.
A falling skydiver straightens her legs to increase her surface area.
This causes the skydiver to accelerate upwards.
Explain why straightening her legs causes the skydiver to accelerate upwards. [2 marks]
The upwards force is greater than the downwards force  because air resistance increases .
Acceleration occurs whenever there is a resultant force. Acceleration will cause an object to either: speed up, slow down or change direction. In this case she is falling downwards so an upwards acceleration will slow her speed (she will not suddenly shoot upwards).