An automobile travels along a straight east–west road in four stages
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
An automobile travels along a straight east–west road in four stages, with a brief halt included.
• Stage 1: 20 km due east at 40 km h⁻¹.
• Stage 2: A halt of 10 min (no distance covered).
• Stage 3: 30 km due east at 60 km h⁻¹.
• Stage 4: 50 km due west at 50 km h⁻¹.
(a) Calculate the total distance travelled and the total time taken, including the halt.
(b) Determine the average speed for the whole journey.
(c) Taking east as positive, find the net displacement and hence the average velocity (indicate its sign).
(d) Find the ratio of the average speed obtained in part (b) to the magnitude of the average velocity obtained in part (c).