The slider block of mass M is moving to the right with speed v when it is acted upon by the forces { F }_{ 1 } and { F }_{ 2 } . If these loadings vary in the manner shown on the graph, determine the speed of the block at t = { t }_{ 3 } . Neglect friction and the mass of the pulleys and cords. Given: M = 40 kg , v = 1.5 m/s , { t }_{ 3 } = 6 s , { t }_{ 2 } = 4 s , { t }_{ 1 } = 2 s , { P }_{ 1 } = 10 N , { P }_{ 2 } = 20 N , { P }_{ 3 } = 30 N , { P }_{ 4 } = 40 N