A block of the mass of 1 kg is moving on the x -axis. A force F acting on the block is shown. The velocity of the block at time t = 2 s is - 3 m s - 1 . What is the speed of the block at time t = 4 s ?

Step-by-step solution

Given, the mass of block m = 1   k g The velocity of the block at time t = 2     s is - 3   m   s - 1 Impulse during t = 2  s to t = 4  s . From the graph, I = A r e a   o f   ΔABC + A r e a   o f   ΔCDE = 1 2 3 - 2 × 5 + 1 2 ( 4 - 3 ) ( - 5 ) = 5 2 - 5 2 = 0 We know that, Impulse = Change in momentum 0 = m v f - m v i ⇒       m v f - m v i = 0 ⇒         m v f = m v i v f = v i = - 3   m &#160