Question

Use the graph below for questions 12 15 Velocity versus Time 10 1 23 456 789 10 Time (s) 2. What is the average acceleration of the particle fromt2s tot9s? 3. What is the instantaneous acceleration at t 5 s?

Answer 1

Average Acceleration: t = 2 s v_i = 2 m/s t = 9 s v_f = 5 m/s < a > = v_f - v_i/delta t = 5 - 2/9 - 2 < a > = 0.4 m/s^2 Instantaneous Acceleration at t = 5 s Here acceleration is constant in between t = 4 s Thus instantaneous acceleration will be similar to avg. acceleration a = 2 - 4/6 - 4 = -2/2 = -1 m/s^2 a = -1 m/s^2 Displacement from t = 4 s to t = 8 s for t = 4 s to t = 6 second average acceleration a = -1 m/.s^2: Here t = delta t = 2 second x_1 = v_it + 1/2 at^2 = 4(2) + 1/2 (-1) (2)^2 x_1 = 8 - 2 = 6 m for t = 6 s to t = 8 s velocity is constant x_2 = vy = 2(2) = 4m Total displacement (x) = x_1 + x_2 = 6 + 4 = 8 m t