IB Physics Speed

/

A tutorial sheet on speed is given below.

  1. Define the word speed.
  2. Is the speed of an object at a certain time equal to its rate of change of distance at this time?
  3. Is the speed of an object at a certain instant always equal to the gradient of the distance-time graph at this instant?
  4. Define the term average speed.
  5. Is average speed equal to distance over time?
  6. A car travels between two towns A and B. The car travels from A to B at a constant speed of 40 km h-1. It immediately returns to A on the same road with a constant speed of 50 km h-1. Is the average speed for the entire journey 45 km h-1?