An automated high-speed commuter train undergoes emergency braking trials.
In the first trial, the automatic system's thinking distance is 18 m18\text{ m}18 m and the braking distance is 64 m64\text{ m}64 m.
Calculate the total stopping distance of the train.
In another trial, a cargo train travels at a speed of 36 m/s36\text{ m/s}36 m/s. After the emergency magnetic brakes are fully applied, it takes 8.0 s8.0\text{ s}8.0 s for the train to come to a complete stop.
Calculate the deceleration of the train. Use the equation:
acceleration=change in velocitytime \text{acceleration} = \frac{\text{change in velocity}}{\text{time}} acceleration=timechange in velocityThe train's braking system is upgraded with an ultra-reactive electromagnetic track brake. The same train travelling at 36 m/s36\text{ m/s}36 m/s now takes only 0.80 s0.80\text{ s}0.80 s to come to a complete stop once the brakes are applied.
A technician claims: "Since the emergency stopping time is ten times shorter, this upgraded braking system makes the cargo and occupants ten times safer in an emergency stop."
Explain why this claim is incorrect, referencing the forces acting on the occupants or cargo.
Suggest one safety feature in a transport vehicle designed to reduce passenger or cargo injury/damage caused by these forces during rapid deceleration.
27 exam-style questions on OCR GCSE Physics Physics on the move. Each one has a worked solution and a mark scheme showing where the marks go.