A and B ran over a distance starting from the same place. The distance-time graph is shown:

Consider the following statements:

1. A ran throughout the given period of time with uniform velocity.

2. A ran throughout the given period of time with uniform acceleration.

3. B stopped running after 2 hours.

4. A ran faster than B near the 2-hr stage.

Which of these statements is/are correct?            

Solution

Stetement-1 is correct: A ran throughout the given period of time with uniform velocity as the slope of the graph does not change. Statement-2 is correct: As the velocity of A remains constant, it can be said that A ran with a zero acceleration. Statement-3 is correct: B stopped running after 2 hours. After, 2 hours the distance travelled by B is not increasing though time is increasing which means B stopped after 2 hours. Statement-4 is correct: A ran faster than B near the 2-hr stage. A was running while B stopped hence this can be said. Distance-Time graph If an object moves along a straight line, the distance travelled can be represented by a distance-time graph. In a distance-time graph, the gradient of the line is equal to the speed of the object. The greater the gradient (and the steeper the line) the faster the object is moving. An increasing gradient on the distance-time graph represents acceleration while a reducing gradient indicates deceleration.