307 Energy Problems Part 2 (45pts)
  • Write all answers in your bound unlined journal

    MATH PROBLEMS need all 4 parts (1pt each)

    1. Free body Diagram
    2. Equations written out
    3. Numbers
    4. Solve and Box your answer
       

    EXAMPLE PROBLEMS
    1. A 15kg rock is 10-m above the ground.
      (follow 306 boulder example)
      1. What is its potential energy when it is 10-m above the ground?
      2. What is its kinetic energy when it is 10-m above the ground?
      3. The boulder begins to fall. What is its potential energy when it is 5-m above the ground? Where did the “lost” potential energy go?
      4. What is the kinetic energy of the boulder when it has fallen 5-m?
      5. What is the kinetic energy of the boulder just before it hits the ground?
    2. When you use a slingshot to fire a rock you stretch the rubber band storing potential energy. If you stretched the rubber band so that it had 100-J of potential energy,
      1. With how much kinetic energy will the rock leave the slingshot?
      2. With how much kinetic energy will the rock leave the slingshot if it loses 10-J to heat & sound?
      3. What is the speed of the projectile if it weighs 0.100kg?
    3. A pendulum has 15-J of potential energy at the top of its swing.
      1. What is its kinetic energy at the bottom of its swing?
      2. At another time the pendulum has 8-J of potential energy. What is its kinetic energy?
      3. For the pendulum in “b”, what will its kinetic energy be if it loses 2-J to heat?
    4. A 1-kg ball is 10-m above a table when it is dropped. It bounces to a height of 7-m.
      1. How much energy is transferred to heat & sound during the bounce?
      2. Explain why this ball cannot bounce to a height of 12-m if it is dropped
      3. What could you do to make the ball bounce to a height of 12-m?
    5. The baseball player does 1234 Joules of work when hitting a baseball into left field. Assuming the baseball landed 100 meters away from home plate,
      1. How much force did the player use to hit the ball?
      2. If the mass of the baseball was 0.149kg, What was its velocity upon release from the bat?

     
    (45pts)WORK Energy Problems 2
     
    1. (17pts) A 5kg rock is 30-m above the ground. Video 59
      1. What is its potential energy when it is 30-m above the ground?
      2. What is its kinetic energy when it is 30-m above the ground?
      3. The boulder begins to fall. What is its potential energy when it is 15-m above the ground? Where did the “lost” potential energy go?
      4. What is the kinetic energy of the boulder when it has fallen 15-m?
      5. What is the kinetic energy of the boulder just before it hits the ground?
    2. (7pts) When you use a slingshot to fire a rock you stretch the rubber band storing potential energy. If you stretched the rubber band so that it had 120-J of potential energy,
      1. With how much kinetic energy will the rock leave the slingshot?
      2. With how much kinetic energy will the rock leave the slingshot if it loses 20-J to heat & sound?
      3. What is the speed of the projectile if it weighs 0.200kg?
    3. (7pts) A pendulum has 20-J of potential energy at the top of its swing.
      1. What is its kinetic energy at the bottom of its swing?
      2. At another time the pendulum has 8-J of potential energy. What is its kinetic energy?
      3. For the pendulum in “b”, what will its kinetic energy be if it loses 1-J to heat?
    4. (7pts) A 2-kg ball is 15-m above a table when it is dropped. It bounces to a height of 12-m.
      1. How much energy is transferred to heat & sound during the bounce?
      2. Explain why this ball cannot bounce to a height of 15-m if it is dropped
      3. What could you do to make the ball bounce to a height of 15-m?
    5. (7pts) The baseball player does 1705 Joules of work when hitting a baseball into left field. Assuming the baseball landed 130 meters away from home plate,
      1. How much force did the player use to hit the ball?
      2. If the mass of the baseball was 0.149kg, What was its velocity upon release from the bat?