1. A 0.25-kg snowball moving at 15 m/s [E] collides and sticks with a 1.9-kg toy truck travelling at 2.8 m/s [W]. Calculate the velocity of the snowball-truck system after the collision. [3 marks] 2. A robin of mass 150 g uses 10 J of energy and speeds up to 15 m/s in level flight. Calculate the initial speed of the robin. [3 marks] 3. An 87-g box is attached to a spring with a force constant of 82 N/m. The spring is compressed 11 cm and the system is released. What is the speed of the box when the spring is released? [4 marks] 4. A 63-kg student stands on a 34-kg cart that is moving with a velocity of 3.2 m/s [W]. The student then jumps off so that her velocity is 1.8 m/s [25 W of N]. Calculate the new velocity of the cart. [6 marks]