1. How much work is done by: (a) a 10 N force acting at 25 above the horizontal when it pulls a 5 kg box is through 2 m across a floor? (b) friction when a 5 kg box is pulled 2 m across a floor by a 3 N force acting at 15 above the horizontal? Assume the coefficient of friction of the floor and the box to be 0.15. 2. A 12 N force acting at 30" above the horizontal pulls a 5 kg box through a distance of 8 m along a horizontal surface. If the coefficient of kinetic friction between the floor and the box is 0.2, how much work done is done by: (a) applied force? (b) normal force? (c) friction? (d) gravity? 3. Starting a lawn mower engine requires one to pull on a cord wrapped around a pulley as depicted in the figure Assuming that the pulley is a cylinder with a radius of 0.02 m, and the force is 320 N, how much rotational work is done in rotating the pulley through 2 revolutions? F Cord Pulley Rotation 4. What is the mechanical advantage of moving a 50 kg box up a 30 incline? 5. What is the potential energy of a: (a) 5 kg object, with respect to the ground, when it is 2 m above the ground? (b) 5 kg object, with respect to the ground, when it 2 m along a 20" inclined plane? (c) spring with a spring constant of 5 N/m when it is stretched 10 cm? 6. What is the kinetic energy of a: (a) 5 g object moving at 10 m/s? (b) 5 g disk, with a radius of 0.2 m, rotating at 5 rad/s about an axis through its center? 7. A 50 N force is applied to a cart at rest. If the force acts horizontally on the cart, what is the speed of the cart after it has moved a horizontal distance of 4 m? 8. A 0.5 g box drops from a height of 5000 cm above the ground without it spinning as it falls. Assuming that air resistance is negligible, when the box is 5 m above the ground, (a) What is its kinetic energy? (b) What is its linear speed? 9. Name a device that converts: (a) Heat to Mechanical energy, (b) Chemical energy to Electrical energy, (c) Solar energy to Mechanical energy, d) Electrical energy to Light, (e) Electrical energy to Heat. 10. A 5 kg box is pushed across a frictionless floor with a horizontal force of 5 N for a distance of 5 m. How much power is used in pushing the box 5 m in 5 s