Tue Jan 31 Today Review hw 5. 5 Read p293-295. (p280) 83,87,91 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=(mv2)/2 K=(mv)2/2 K=2mv2 K=(mg)/h 25 of 30

The SI units for energy and work are: Newtons Watts Joules Amperes 25 of 30

Kinetic energy is a ____ quantity Tensor Scalar Vector Negative 25 of 30

The transfer of energy by mechanical means is called _______. Heat Machination Work Force 25 of 30

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. 25 of 30

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. 22 of 30

If an object’s speed doubles its kinetic energy: Quadruples Doubles Is cut in half. Doesn’t change 24 of 30

The kinetic energy of a 4.0 kg object moving at 3.0 m/s is:

How much work is done if you push a 5 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 23 of 30

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 25 of 30

_____ describes how quickly energy is transferred. Kinetic energy Velocity Power Pressure 24 of 30

The SI units of power are: Joules Teslas Pascals Watts 25 of 30

A Watt is equal to N m J s N/m2 J/s 24 of 30

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 24 of 30

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 24 of 30

________ is where we decide to set gravitational potential energy to zero. The null zone Outer space The reference level On top of spaghetti 24 of 30

Which of the following is a conservative force? Friction Thrust Gravity Air resistance 25 of 30

A 4. 0 kg object is moving has 72 J of kinetic energy when it is 3 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 25 of 30

A 4. 0 kg object has 72 J of kinetic energy when it is 3 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 25 of 30

A 4. 0 kg object has 72 J of kinetic energy when it is 3 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 22 of 30

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 25 of 30

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 24 of 30

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 25 of 30

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% 25 of 30

A pulley is used to raise a 2. 0 kg object 50 cm off of the table 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 24 of 30

A pulley is used to raise a 2. 0 kg object 50 cm off of the table 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 24 of 30

A pulley is used to raise a 2. 0 kg object 50 cm off of the table 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 22 of 30

A pulley is used to raise a 2. 0 kg object 50 cm off of the table 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% 25 of 30

If a machine has a mechanical advantage of 5 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

A pulley is used to raise a 2. 0 kg object 50 cm off of the table 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