Unit 10- Energy, Work, Simple Machines

Question 0

Example of energy is …

Answer 0

1. Tree branches swaying in the wind

Question 1

What is energy?

Answer 1

The ability to do work

a) not the same as matter doesn’t occupy space or have mass
b) can only be described by what it does
c) can be measured but only effects can be seen

Question 2

What’s the source of mechanical energy and examples?

Answer 2

Source - moving parts

Examples - muscles, machines, wind, rivers

Question 3

What’s the source of Chemical Energy and examples?

Answer 3

Source - molecules

Examples - fossil fuels, FOOD, batteries

Question 4

What’s the source of Solar Energy and examples

Answer 4

Source - Sun

Examples - heat, light, ultraviolet radiation

Question 5

What’s the source of electrical energy and example

Answer 5

Source - electrons

Examples - lighting, electrical currents

Question 6

What’s the source of heat energy and examples?

Answer 6

Source - movement of particles in a substance (friction)

Examples - rubbing hands together to make them warm

Question 7

What’s the source of Nuclear Energy and examples

Answer 7

Source - atomic nuclei ( protons or neutrons being shot out of unstable isotopes)

Examples - uranium

Question 8

What’s the source of Geothermal Energy and examples?

Answer 8

Source - heat from inside the earth

Examples - hot springs, geysers

Question 9

What’s the source of Sound Energy and examples?

Answer 9

Source - vibrations of matter

Examples - thunder, piano, guitar, singing, Amy

Question 10

What’s the source of Light Energy and examples

Answer 10

Source - waves of energy bundles, photons

Examples - sun, light bulb

Question 11

What’s renewable energy?

Answer 11

Energy that’s for all practical purposes everlasting

Sun, wind, falling water, tides, geothermal biomass

Question 12

Energy transformations

Answer 12

Energy is being transformed in everyday activities from one form to another

Question 13

Examples of energy transformation

Answer 13

Running a mile in gym - chemical to mechanical

Question 14

Kinetic and Potential energy

Answer 14

All forms exist as either kinetic or potential

Question 15

Potential energy and examples

Answer 15

Energy of position, higher position is greater potential energy, a resting object has potential energy

Examples - parked car, battery

Question 16

WORK

Answer 16

Occurs when a force causes an object to move in the direction the force is applied

a) work involves motion not just effort
b) only happens when force on a object is in the same direction as objects motion
c) if force is at angle only part of the force that’s in the same direction as the motion does work

Question 17

Formula for work

Answer 17

W=FxD
work= force x distance

W= (m•a) •d

Measured in Joules

Question 18

Work and distance

Answer 18

Distance in the work equation is the distance an object moves while the force is being applied

Question 19

Work and kinetic energy

Answer 19

Doing work on an object increases kinetic energy

Question 20

POWER

Answer 20

How quickly work is done

Power =work \time

Units- watts

Question 21

Energy Transfer

Answer 21

Amount of work done is the amount of energy transfer and can be expressed as Power = energy transfer/ time

Question 22

Machine

Answer 22

Device that makes work easier

a) change the way work is done
b) not change the amount o work done

Question 23

Input force

Answer 23

Force u exert on a machine

Question 24

Output force

Answer 24

The resisting force or the work a machine does to move an object over some distance

Question 25

Mechanical Advantage

Answer 25

The number of times the input force is multiplied by a machine

Mechanical force= output force / input force