Question

The velocity-time plot for a particle moving on a straight line is shown in the figure.
Figure

(a) The particle has a constant acceleration.
(b) The particle has never turned around.
(c) The particle has zero displacement.
(d) The average speed in the interval 0 to 10 s is the same as the average speed in the interval 10 s to 20 s.

Answer 1

(a) The particle has a constant acceleration.
(d) The average speed in the interval 0 s to 10 s is the same as the average speed in the interval 10 s to 20 s.

Explanation:
(a) The slope of the v–t graph gives the acceleration. For the given graph, the slope is constant. So, acceleration is constant.

(b) From 0 to 10 seconds, velocity is in positive direction and then in negative direction. This means that the particle turns around at t = 10 s.

(c) Area in the v–t curve gives the distance travelled by the particle.
Distance travelled in positive direction$\ne$Distance travelled in negative direction
∴ Displacement$\ne$Zero

(d) The area of the v–t graph from t = 0 s to t = 10 s is the same as that from t = 10 s to t = 20 s. So, the distance covered is the same. Hence, the average speed is the same.