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Intro to Energy & Kinetic Energy quiz #4

컨트롤 버튼이 '내비게이션' 모드로 변경되었습니다.
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이 집합의 용어 (33)

  • The kinetic energy from an object's motion always changes when which factor changes?
    Kinetic energy changes when speed changes.
  • What two forms of energy are associated with mechanical energy?
    Kinetic energy and potential energy.
  • If 320 joules of work are done by a force of 80 newtons, over what distance was the force applied?
    Distance = Work / Force = 320 J / 80 N = 4 meters.
  • How do machines multiply force without multiplying work?
    Machines trade force for distance; they increase force by decreasing the distance over which it is applied, keeping work constant.
  • How far up a hill will a car coast before rolling back down, in terms of energy?
    A car will coast up the hill until its kinetic energy is fully converted into potential energy.
  • If a 16 N force is applied to an object and 96 J of work is done, how far was the object moved?
    Distance = Work / Force = 96 J / 16 N = 6 meters.
  • Is work done if you pull a child in a wagon?
    Yes, work is done when you pull a child in a wagon.
  • When is kinetic energy transferred from one object to another?
    Kinetic energy is transferred during collisions or interactions between objects.
  • Why is energy required to get an object moving?
    Energy is required to overcome inertia and provide the object with kinetic energy.
  • What is true about a car moving at constant velocity?
    A car moving at constant velocity has constant kinetic energy.
  • What is the unit of measurement for work?
    The unit of work is the joule (J).
  • What is the energy transformation in an electric motor?
    An electric motor converts electrical energy into mechanical energy.
  • How is work defined in physics?
    Work is defined as the transfer of energy by a force acting over a distance.
  • If the total energy of a block-spring system is doubled, what happens to the amplitude?
    If total energy is doubled, amplitude increases by a factor of √2.
  • What is the potential energy of a spring with stiffness 100 N/m compressed by 0.1 m?
    Potential energy = 0.5 × 100 N/m × (0.1 m)^2 = 0.5 joules.
  • What is the relationship between work and energy?
    Work is the process of transferring energy to or from an object.
  • What is an example of work being done on an object?
    Lifting a box off the ground is an example of work being done.
  • What is an example of potential energy?
    A stretched rubber band has potential energy.
  • What is the relationship between kinetic energy and potential energy?
    Kinetic and potential energy can transform into each other, but their sum is conserved in a closed system.
  • What energy transformation occurs when a skydiver first jumps from a plane?
    Potential energy is converted into kinetic energy.
  • How much work does a battery connected to a 21.0-ohm resistor perform in one minute?
    Work done = Power × time; Power depends on voltage and resistance (not provided), so use W = P × t.
  • What is the car's speed after coasting down the other side of a hill, in terms of energy?
    The car's speed is determined by the conversion of potential energy back into kinetic energy.
  • What is the speed of an object at half its maximum height during vertical motion?
    At half maximum height, use energy conservation: KE = total energy - PE; solve for speed using KE = 0.5mv^2.
  • What happens in terms of energy when a moving car hits a parked car?
    Kinetic energy is transferred from the moving car to the parked car, possibly causing both to move.
  • How do potential and kinetic energy compare?
    Potential energy is stored due to position; kinetic energy is due to motion. Both can transform into each other.
  • What energy transformation occurs in an electric pencil sharpener?
    Electrical energy is converted into mechanical energy.
  • What does the mechanical energy of a system include?
    Mechanical energy includes both kinetic and potential energy.
  • How far will you travel in 3 minutes running at a rate of 6 m/s?
    Distance = speed × time = 6 m/s × 180 s = 1080 meters.
  • As an object in motion becomes heavier, what happens to its kinetic energy?
    Its kinetic energy increases.
  • If a speeding truck hits a wall, what type of energy is in the motion of the truck?
    The truck's motion is kinetic energy.
  • What does total stopping time consist of?
    Total stopping time consists of reaction time and braking time.
  • Why is making rough estimates of physical quantities useful?
    Making rough estimates helps check the reasonableness of answers and understand physical situations.
  • How do you find the kinetic energy of a car at the top of a loop?
    Use KE = 0.5 × mass × (speed at top)^2.