Part B: Mechanical Systems (10 marks) 1. At a fitness training challenge you are asked to push a 25kg crate across a gym floor. Explain what part of the push is static friction and what part of the push is kinetic friction. (3 marks) 2. How much work must be done to lift a 39kg child onto a countertop that is 1.2m off the ground? (2 marks) 3. A 4.0m long bar is being used as a first-class lever. It has a load of 1400N placed on one end that is located 0.80m from the fulcrum. The effort is being applied at the other end. a) Draw a labeled diagram of the lever. ( 2 marks) b) Determine the effort force needed to balance the load ( 3 marks)