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Work, energy, and power

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  • TRUE or FALSE. Gravitational potential energy = force x distance
    TRUE
  • A diver climbs a 6 m ladder to reach a diving board. As she climbs to the board, which type of energy is increased?
    gravitational potential
  • TRUE or FALSE. Velocity has more of a mathematical impact on kinetic energy than mass does.
    TRUE
  • What is the unit of potential and kinetic energy?
    Joules
  • Which pair of quantities can be expressed using the same unit?
  • It is the energy due to its position and condition. Also known as the stored energy.
    potential energy
  • If the work done increase, the the power is .........
    increases
  • What is the formula for power?
    P = W/t
  • What is the power of a bike that does 3600 J of work in 48 seconds?
    P = W/t = (3600)/(48) = 75 J/s
  • Which pair of quantities can be expressed using the same unit? A. acceleration-velocity; B. work-energy; C. power-displacement; D. weight-potential energy
    B. work-energy
  • What is the work-energy theorem?
    work = change in energy
  • TRUE or FALSE. Force has no effect on work.
    FALSE
  • What is the unit of work?
    Joule
  • True or false: the law of conservation of energy states that potential energy can be completely converted to kinetic energy.
    True
  • If it takes 20 N to move an object 2 meters, how much work has been done?
    40 J
  • It is the energy due to its motion.
    kinetic energy
  • Calculate the kinetic energy of a 75 kg man walking at 1.2 m/s.
    KE=1/2 mv^2 = 1/2 (75)(1.2)^2 = 54 J
  • Which pair of quantities can be expressed using the same unit?
  • A rock sitting at the edge of a cliff. It is potential energy. TRUE or FALSE.
    TRUE
  • A car is sitting on a hill 20 m high. Find the mass of the car if it contains 352800 J of potential energy.
    1800 kg
  • A ball is dropped from a certain height. What happens to the kinetic energy of the rubber ball when it hits the ground if no heat and sound is produced?
    kinetic energy will change into potential energy
  • TRUE or FALSE. If an object reaches a higher height, it will gain more potential energy.
    TRUE
  • TRUE or FALSE. If you double an object's mass, this will have more effect on the kinetic energy than it would if you doubled its velocity.
    FALSE. KE = 1/2mv^2
  • What is the equivalent unit of one joule of work?
    1 Nm
  • List the two types of energy.
    Potential and kinetic energy
  • How much work is done by a person who pulls a cart with a force of 50 N if the cart moves 20 m in the direction of the force?
    W = Fs = (50)(20) = 1000 J
  • Farhan toy truck haas a mass of 6 kg. If he pushes it with a force of 10 N, a distance of 4 m, how much work has he done on the truck?
    W = fs = (10)(4) = 40 J
  • What two factors must be present for work to be done upon an object
    force and moving distance
  • The law of conservation of energy states ..........
    energy cannot be created or destroyed
  • What is the formula or equation for kinetic energy?
    KE = 1/2 mv^2
  • What are the two factors affecting kinetic energy?
    mass and velocity
  • When a roller coaster is at the top of a hill, it has GPE or KE?
    GPE
  • What is the formula or equation for potential energy?
    PE = mgh
  • TRUE or FALSE. Energy can be destroyed.
    FALSE
  • What is being transferred as you do work?
    energy
  • What are the two factors affecting potential energy?
    mass and height