Chapter 12- Work And Energy

Question 1

Block and tackle

Answer 1

When multiple pulleys are combined together to act as one contraption.

Question 2

Closed system

Answer 2

When the energy is too small and is ignored

Question 3

Work

Answer 3

Transfer of energy to an object from a force causing the object to move in the direction of the force

Question 4

Power

Answer 4

Quantity measuring the rate of work or transformed energy. Power=work/time

Question 5

Mechanical advantage

Answer 5

Measures how much force or distance is multiplied by a machine. Mechanical advantage=output force/input force=input force/output force.

Question 6

Joule

Answer 6

SI Unit of work. Newtonsmeters. Joules is also equivalent to 1kgm^2/s^2.

Question 7

Watt

Answer 7

SI Unit of power. Abbreviation is W, not to be confused with work, italics W.

Question 8

Simple machine

Answer 8

Basic types of machines that make up other forms of machines. Pulley, simple lever, simple inclined plane, wedge, screw, and wheel and axel.

Question 9

Compound machine

Answer 9

Two or more simple machines put together to make a bigger machine. Like the brakes and tires of a bike.

Question 11

Efficiency

Answer 11

Usually a percentage amount that measures useful work output to work input. Efficiency=useful work output/work input.

Question 12

Elastic potential energy

Answer 12

Energy stored in stretchy or elastic material

Question 13

First class lever

Answer 13

Has the fulcrum pointed at the middle of the arm.

Question 14

Gravitational potential energy

Answer 14

Work of any two objects that have distance between them

Question 15

Lever

Answer 15

An arm that has a Fulcrum(balance piece) attached.

Question 16

Incline plane

Answer 16

An elevated platform, like a ramp.

Question 17

Kinetic

Answer 17

The highest point and moving of an object

Question 18

Non mechanical energy

Answer 18

Doesn’t affect a system on a large scale

Question 19

Mechanical

Answer 19

Amount of work an object does because of the potential and kinetic energies

Question 20

Perpetual motion machine

Answer 20

Theoretical machines that could go on forever without any input energy.

Question 21

Open system

Answer 21

When energy flows freely

Question 22

Pulls.

Answer 22

Modified levers that has a wheel of some kind on it.

Question 23

Second class lever

Answer 23

Fulcrum at the end with the output force in the middle and the input force at the end opposite to the fulcrum

Question 23

Potential energy

Answer 23

The lowest point

Question 24

Third class lever

Answer 24

Fulcrum at the end, the input force at the middle and the output force at the opposite end from the fulcrum.

Question 25

Screw

Answer 25

Incline plane wrapped around a cylinder to hold parts together.

Question 26

Wedge

Answer 26

A piece that is forced into something to break apart. Like an axe splitting wood.

Question 27

Wheel and axel

Answer 27

Made of a lever or pulley connected to a shaft. Normally used to mobilize an object.