| A | B |
|---|
| The metric unit used to measure WORK is: | joules |
| The efficiency of a machine is usually expressed in: | percent |
| What LAW explains how it is impossible to have a machine with an efficiency of 110%? | The law of conservation of energy |
| Work is defined as: | Force X distance (moving in a direction parallel to the force) |
| POWER is defined by: | work (joules) / time (sec) |
| The metric unit used to measure power is: | watts |
| Potential energy is energy due to: | the height of the object |
| What is the metric unit used to measure force? | Newton |
| Potential Energy | stored energy |
| Kinetic Energy | energy of motion |
| Electrical Energy | energy associated with electrons moving through a wire or circuit |
| Nuclear Energy | energy produced when atoms split apart (fission) or when they join (fusion) |
| Chemical Energy | energy released when chemical reactions take place |
| Radiant Energy | energy from the sun; CAN move through empty space |
| Sound Energy | energy of vibrations; CANNOT move through empty space |
| Thermal Energy | energy due to motion of atoms; object feels hot |
| Energy | The ability to do work |
| Power | The rate at whih work is done |
| Efficiency | The ratio of the work output to the work input |
| When a force is applied that moves an object in the direction of the applied force, ______ is done. | work |
| When a ball is thrown into the air, the potential energy gained must come from its kinetic energy. As the ball gains potential evergy, will its speed increase or decrease? | decrease |
| A boxer lifts his 10 Kg gloves 3 meters and carries them 12 meters to the ring. How much work did the boxer do? | 30 Joules |
| How much power is necessary to do 100 Joules of work in 1 minute? | P = W/t 100 J/60 secs = 1.67 Watts |
| On a roller coaster, where is kinetic energy the highest? | At the lowest point |
| On a roller coaster, where is potential energy the highest? | At the highest point |
| How long does it take a 100 Watt bulb to use up 500 Joules of energy? | 5 seconds t = W/P = 500/100 |
| A boat pulls a skiier 5 kilometers with a force of 500 N for 30 minutes. What is the power of the boat? | P = 1,388.9 Watts (be sure to convert km to m and minutes to secs) |
| As a car slows, most of its kinetic energy is converted by the brakes to what form of energy? | thermal energy |
| What energy transformations occur when you turn on a solar calculator? | Radiant energy from sun, converts to chemical energy in battery, chemical converts to electrical to turn it on |
| What is the potential energy of a 5 kg ball thrown 5 meters high at the top of its path? | Ep = mgh = 5 x 9.8 x 5 = 245 J |
| What is the kinetic energy of a 250 kg kite flying at a speed of 5 m/s? | Ek - .5mv2 = .5 x 250kg x 25 m/s = 3125 J |
