A van of mass 2500 kg travels at 18 m/s. The driver makes an emergency stop. The braking distance is 27 m.
Calculate the deceleration of the van while it is braking.
Use the equation
v2−u2=2×a×xv^2 - u^2 = 2 \times a \times xv2−u2=2×a×x
Calculate the braking force on the van.
A box of mass 20 kg is in the back of the van. The box is not fixed in place.
Explain why the box may slide forwards during the emergency stop.
Use a calculation in your answer.
126 exam-style questions on Edexcel GCSE Physics 2.5 Stopping and braking distances, covering 2.5.1 Stopping distance and reaction time, 2.5.2 Factors affecting stopping distance, 2.5.3 Dangers of large decelerations, and 2.5.4 Braking distance and initial speed. Each one has a worked solution and a mark scheme showing where the marks go.