1. A 30 N chest was pulled 5 m across the floor at a constant speed by applying a force of 50 N at an angle of 30". Determine the amount of work done by: (a) The tension force T. (b) The force of gravity. 2. Evaluate A.B and the angle between A and B: (a) A = 3i - 4j; B= -21 + 6j (b) A = -41 + 2j; B = -1-2j 3. Determine the amount of work done by a force F = (-4.01 -6.0j) N acting on a particle that movers through a displacement Ar = (-3.01 + 2.0]) m. 4. What force does the most work? A. 10 N force B. & N force ION 8 N C. 6 N force D. They all do the same amount of work Ar AP 5. As you ride an elevator going upward at constant speed, the work done on you by the normal force from the floor of the elevator is (A) Negative (B) zero (C) positive (D) Negative, zero or positive depending on the speed of the elevator6. Bullet I is half the mass of bullet 2. Both bullets are fired so that they have the same speeds. If the kinetic energy of bullet 1 is K, the kinetic energy of bullet 2 must be (A) 2K (B) K/2 (C) 4K (D) K/4 (E) K (F) KV2 7. The speed of a 2.5-kg mass changes from 15 m/'s to 35 m/'s. Determine the net work done on this mass. 8. A 2.5-kg mass moves at a constant speed of 35 m/'s over a distance of 150 m. Determine the net work done on this mass. 9. What is the total work done on an object moving with constant velocity? (A) Positive (B) Negative (C) Zero 10. An object moving along the x axis is acted upon by a force Fx that varies with position as shown. How much work is done by this force as the object moves from x = 0 m to x = 12 m? 11. A 2.0-kg particle has an initial velocity of (5i - 4j) m/s. Sometime later, its velocity is (7i + 3]) m/'s. How much work was done by the resultant force during this time interval, assuming no energy is lost in the process? 12. A skier of mass 82.0 kg comes down a frictionless ski run that is circular (radius = 30 m). What is the change in her gravitational potential energy when she moves from point A to point B? Fi