Velocity-time Graph

Velocity-time Graph Study the graph of velocity versus time for a body that is moving along a straight line and answer the questions which follow it. 1. Read or calculate the velocity of the body at 2, 4, 6, 8 s. 2. Mention periods during which velocity is uniform. 3. Mention period during which acceleration is zero. 4. What is the acceleration of the body during last 2 s of its journey ? 5. When does the body change its direction of motion ? 6. How far is the body from its point of start after 7 s ? 7. How much distance does it move in 7 s ? 8. What is the average velocity of the body over 7 s ? Answers : 1. Velocity at 2, 4, 6 and 8 s respectively is 8, 0, -4 and 0 m/s. 2. Velocity is uniform between 1 and 3 s ; and 5 and 7s. 3. Acceleration is zero between 1 and 3 s ; and 5 and 7 s. 4. Acceleration during the last 2 s : 2 0 ( 4) 2 2 v u a ms t − − − − = = = 5. After 4 s. 6. Net displacement in 7 s : 1 1 (2 4)(8) (2 3)( 4) 24 ( 10) 14 2 2 + + + − = + − = m 7. It moves 24 + 10 = 34 m 8. Average velocity : 1 34 4.7 7 displacement velocity ms time − = = =