Distance travelled versus time continued

Sometimes the vehicle does not travel at a steady rate and often slows down , speeds up and stops. The distance-time graph on the right shows the distance covered by a vehicle over a period of 7 hours.

Segment "A" of the graph shows the vehicle covering the distance at a steady rate.

Segment "B" also shows the vehicle covering the distance at a steady rate albeit a little slower than section "A".

At the 4 hour mark the section "C" the vehicle has stopped. This is obvious by the straight line. The driver may actually be having a 2 hour rest 4 hours after the journey started.

Six hours after the journey commenced the vehicle speeds away to cover 40 kilometres in 1 hour. The steady rate with which it covers the distance is greater than in section "A" and "B ".

The distance-time graph, above, shows the distance covered by two vehicles over time. Vehicle "B" is 80km from Home while vehicle "A" starts its journey from Home.

Do both vehicles cover the 80km distance at the same rate?


A border guard(Jonathon) 80 km from Base starts his journey back at the same time as a second border guard(Irene) starts her journey to the border post. Both guards commenced their journeys at 10.00am. The distance each guard is from the Base and the time is recorded by a computer on a graph (left).

Irene never made it to the border. People were questioned and gave the following statements. Pick the ones that are false and give a reason.

Jonathon " As I was driving along I saw Irene drive past me at a very fast speed" Jonathon " I got back about 6.00pm "
Witness(1) " She stopped by the road side just after 1.30pm"
Witness(2) " I saw a car crash into a tree about 30 km from the border"
Cafe owner " She had coffee in my shop at 11.30am"


Continue with speed