Test: Average Velocity and Average Speed - ACT MCQ

The total change in displacement = 20 m. Total time taken = 5 s. Average velocity = total change in displacement/total time taken = 20/5 = 4 m/s.

The average velocity is zero. The ball covers positive displacement when it goes up and negative displacement when it comes down. Hence the total displacement is zero. Therefore, the average velocity is zero.

From first equation of motion we have, v = u + at, which implies that a = 5 m/s². From second equation of motion we have s = ut + (1/2)at², which implies that s = 40 m. Average speed = s/t = 40/4 = 10 m/s.

Average speed is the total distance divided by total time taken. Total displacement (d = vt) = 20×20 + 15×10 + 10×5 = 600 m. Total time = 20 + 10 + 5 = 35 s. Therefore, average speed = 600/35 = 17.14 m/s.

The correct formula is v = x/t. Average velocity is total change in displacement divided by total change in time. v = dx/dt is the formula for instantaneous velocity.

Take any point on the circular path. The car moves in a circle and hence will come back to the same point after a definite time interval. Therefore, the displacement is 0. Hence, the average velocity is zero.

When the body is moving with terminal velocity, the velocity does not change. It means that equal displacement is being covered in equal time intervals. Hence the average velocity remains constant.

Average speed is the ratio of total distance to total time. Instantaneous speed is the ratio of instantaneous change in distance to instantaneous change in time. Average speed can be equal to instantaneous speed but is usually less than that.

Average speed is defined as total distance divided by total time. The total distance is 150 km and total time taken is 3 Hrs, therefore average speed = 150/3 = 50 km/hr.

As the ball falls down, its velocity increases. This is because of the acceleration due to gravity. Hence the graph looks like a straight line with positive slope. The first equation of motion verifies this.