1. Usually, when we say that something has "lost energy" we really mean that some of the energy was converted into a form that is not to us. 2. Mechanical forms of energy include and allows you to calculate the energy added or removed from a system using a force. 4. A 2.6 kg rock is dropped from a height of 10 m. With what speed will it strike the ground. Ignore air resistance. Solve using conservation of energy (start with Ebefore = Eafter). 5. A ball is thrown straight up leaving the player's hands at at 7.5 m/s. If air resistance is ignored, how high can the ball travel? Show all work starting with Ebefore = Eafter. 6. Explain the energy transfers involved in pole vaulting. 7. A skier starts from rest at the top of a frictionless incline of height 20 m as shown here. How fast is the skier travelling at the bottom of the hill? Show all work starting with Ebefore = Eafter