The jet plane has a mass M and a horizontal velocity { v }_{ 0 } when t = 0. If both engines provide a horizontal thrust which varies as shown in the graph, determine the plane’s velocity at time { t }_{ 1 } . Neglect air resistance and the loss of fuel during the motion. Units Used:Mg = { 10 }^{ 3 } kg , kN = { 10 }^{ 3 } N Given: M = 250 Mg , { v }_{ 0 } = 100 m/s , { t }_{ 1 } = 15 s , a = 200 kN , b = { 2 kN/s }^{ 2 }