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The formula for kinetic energy is:

Tue Jan 31 Today Review hw 5.5 Read p293-295 (p280) 83,87,91 (p307-9) 56, 61,76,81,82 ch 10-11 test next Tue. or Wed.!. The formula for kinetic energy is:. K=(mv 2 )/2 K=( mv ) 2 /2 K=2mv 2 K=(mg)/h. 0 of 30. The SI units for energy and work are:. Newtons Watts Joules Amperes.

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The formula for kinetic energy is:

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  1. Tue Jan 31 Today Reviewhw 5.5 Read p293-295 (p280) 83,87,91 (p307-9) 56, 61,76,81,82ch 10-11 test next Tue. or Wed.!

  2. The formula for kinetic energy is: • K=(mv2)/2 • K=(mv)2/2 • K=2mv2 • K=(mg)/h 0 of 30

  3. The SI units for energy and work are: • Newtons • Watts • Joules • Amperes 0 of 30

  4. Kinetic energy is a ____ quantity • Tensor • Scalar • Vector • Negative 0 of 30

  5. The transfer of energy by mechanical means is called _______. • Heat • Machination • Work • Force 0 of 30

  6. Work is done when: • A force acts through a distance. • A hot object touches a cold object. • A force acts perpendicular to a displacement • You sleep on the job. 0 of 30

  7. Energy stored in an object that has been lifted in a gravitational field is called: • Elastic potential energy • Gravitational potential energy • Chemical potential energy. • Thermal energy. 0 of 30

  8. If an object’s speed doubles its kinetic energy: • Quadruples • Doubles • Is cut in half. • Doesn’t change 0 of 30

  9. The kinetic energy of a 4.0 kg object moving at 3.0 m/s is: • 12 J • 18 J • 36 J • 48 J 0 of 30

  10. How much work is done if you push a 5.0 kg box 12 meters across the floor while applying a 10.0 N force? • 50 J • 60 J • 120 J • 600 J 0 of 30

  11. How much work do you do if you lift a 6.0 kg object 50 cm up? • None • 3.0 J • 30 J • 3.0 kJ 0 of 30

  12. _____ describes how quickly energy is transferred. • Kinetic energy • Velocity • Power • Pressure 0 of 30

  13. The SI units of power are: • Joules • Teslas • Pascals • Watts 0 of 30

  14. A Watt is equal to • N m • J s • N/m2 • J/s 0 of 30

  15. I have 1.2 kW microwave. How much electrical energy is converted if I heat something on high for 30 seconds? • 40 J • 400 J • 600 J • 36 kJ 0 of 30

  16. If the power output of a motor is 65 W, how long does it take to do 195 J of work? • 1.95 seconds • 3.0 seconds • 260 seconds • 3.5 hours 0 of 30

  17. ________ is where we decide to set gravitational potential energy to zero. • The null zone • Outer space • The reference level • On top of spaghetti 0 of 30

  18. Which of the following is a conservative force? • Friction • Thrust • Gravity • Air resistance 0 of 30

  19. A 4.0 kg object is moving has 72 J of kinetic energy when it is 3.0 m above the reference level. Its speed is • 2.0 m/s • 5.0 m/s • 6.0 m/s • 192 m/s 0 of 30

  20. A 4.0 kg object has 72 J of kinetic energy when it is 3.0 m above the reference level. Its total mechanical energy is • 0.0 J • 72 J • 120 J • 192 J 0 of 30

  21. A 4.0 kg object has 72 J of kinetic energy when it is 3.0 m above the reference level. Once it falls down to the reference level it will have a kinetic energy of • 72 J • 120 J • 192 J • 0.0 J 0 of 30

  22. Simple machines can NOT • Multiply the force that is exerted • Multiply the work that is done • Change the direction a force is exerted • Change the speed 0 of 30

  23. The mechanical advantage of a simple machine describes • How much the machine multiplies the work you do • How much the distance is multiplied • How much the force is multiplied • How much the power is multiplied 0 of 30

  24. The efficiency of a machine describes: • The ratio of the output work to the input work • The ratio of the output force to the input force • The ratio of the output distance to the input distance 0 of 30

  25. If a machine has a mechanical advantage of 5.0 how much force must you exert to lift a 60 kg object? • 60 N • 120 N • 300 N • 3.0 kN 0 of 30

  26. An input of 8.0 kJ of work is is provided to a machine that exerts a 2.0 kN force through a distance of 3.0 meters. What is the efficiency? • 25% • 37.5 % • 75% • 133% 0 of 30

  27. A pulley is used to raise a 2.0 kg object 50 cm off of the table. The work done BY the machine is: • 1.0 kJ • 100 J • 10.0 J • 1.0 J 0 of 30

  28. A pulley is used to raise a 2.0 kg object 50 cm off of the table. The person pulling the string exerts a force of 8.0 N through a distance of 2.0 m. How much work is done by the person? • 1.0 J • 10.0 J • 4.0 J • 16 J 0 of 30

  29. A pulley is used to raise a 2.0 kg object 50 cm off of the table. The person pulling the string exerts a force of 8.0 N through a distance of 2.0 m. The mechanical advantage of the machine is • 4.0 • 2.5 • 2.0 • 0.50 0 of 30

  30. A pulley is used to raise a 2.0 kg object 50 cm off of the table. The person pulling the string exerts a force of 8.0 N through a distance of 2.0 m. The efficiency of the machine is • 31% • 63% • 100% • 160% 0 of 30

  31. A pulley is used to raise a 2.0 kg object 50 cm off of the table. The person pulling the string moves their hand 2.0 m. What is the IMA of the machine? • 4.0 • 2.5 • 0.25 • 10.0 0 of 30

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