unit 4

Question 1

work

Answer 1

force applied through a distance

Question 2

the direction of the force that you apply to an object affects how much ___ you do on it

Answer 2

work

Question 3

when ____ + _____ are parallel, w=fd

Answer 3

force, motion

Question 4

when force is _____ to motion, the work from that force is ____

Answer 4

perpendicular, 0

Question 5

you can only do ____ on an object while applying ____ on an object

Answer 5

work, force

Question 6

device that changes the force/increases the motion from work

Answer 6

machine

Question 7

machine that does work with only 1 movement of the machine

Answer 7

simple machine

Question 8

examples of a simple machine

Answer 8

lever, pulley, wheel and axle, inclined plane, screw, wedge

Question 9

combination of 2 plus simple machines

Answer 9

compound machine

Question 10

examples of compound machine

Answer 10

scissors, bicycle

Question 11

machines can increase for ____ increase speed

Answer 11

or

Question 12

the ratio of output work to input work

Answer 12

efficiency

Question 13

what is efficiency measured in

Answer 13

%

Question 14

efficiency equation

Answer 14

e = w out/w in x 100

Question 15

how are machines made effeicient?

Answer 15

reducing friction (adding lubricant- oil/grease)

Question 16

ratio of the output force to input force

Answer 16

mechanical advantage

Question 17

mechanical advantage equation

Answer 17

MA = Fout/ Fin

Question 18

force that a person/ device applies to a machine

Answer 18

input force

Question 19

force that the machinr applies to another object

Answer 19

output force

Question 20

the ability to cause change

Answer 20

energy

Question 21

what can energy be described as?

Answer 21

the ability to do work

Question 22

what is energy measured in?

Answer 22

joules

Question 23

anything around which you can imagine a boundary

Answer 23

system

Question 24

a system can be ____ or a _____ of objects

Answer 24

single; group

Question 25

true or false: when 1 system does work on a 2 system, energy is transferred from one sytem to the second system

Answer 25

true

Question 26

what are the different forms of energy?

Answer 26

mechanical chemical radiant electrical

Question 27

energy due to motion

Answer 27

kinetic energy

Question 28

what type of energy depends on objects mass and speed

Answer 28

kinetic energy

Question 29

kinetic energy equation

Answer 29

KE = 1/2 mv^2

Question 30

energy stored due to interactions between objects

Answer 30

potential energy

Question 31

energy stored by compressing or stretching an object

Answer 31

elastic potential energy

Question 32

energy due to chemical bonds

Answer 32

chemical potential energy

Question 33

energy due to the gravitational forces between objects

Answer 33

gravitaional potential energy

Question 34

the GPE of a system with just earth and the object depends on objects ___, earths ____ and object ____

Answer 34

mass, gravity, height

Question 35

near earths surface, g = _____

Answer 35

9.8 n/kg

Question 36

GPE equation

Answer 36

GPE = mgh

Question 37

GPE varies with chosen ____

Answer 37

refence level

Question 38

law of conservation of energy

Answer 38

energy cannot be created or destroyed

Question 39

true or false: energy cannot convert from 1 form to another and cannot transfer 1 place to another

Answer 39

false; can

Question 40

the universal principle states that the _____ ______ remains a constant

Answer 40

total energy

Question 41

the sum of the kinetic and potential energy of the objects in a system

Answer 41

mechanical energy

Question 42

mechanical energy examples

Answer 42

kinetic, elastic, potential, gravitational potential energy

Question 43

energy transformations happen during _____ _____ when an object moves in a curved path

Answer 43

projectile motion

Question 44

what type of energy does fraction and air resistance convert some mechanical energy to?

Answer 44

thermal energy

Question 45

what type of energy does feul store ?

Answer 45

chemical potential energy

Question 46

the rate at which energy is converted

Answer 46

power

Question 47

power equation

Answer 47

P = e/t energy/time

Question 48

power is measured in what?

Answer 48

watts

Question 49

1 watt = 1 ____ per second

Answer 49

joule

Question 50

energy from food is measured in ____

Answer 50

calories

Question 51

every gram of foos fat = how many calories of energy?

Answer 51

10

Question 52

carbs and proteins each = how many calories of energy per gram?

Answer 52

5

Question 53

everythinng out body does needs what?

Answer 53

energy

Question 54

radiant energy comes from what type of energy

Answer 54

electrical energy

Question 55

when an object is in freefall, kinetic energy _____, while GPE _____

Answer 55

increases; decreaases

Question 56

what energy comes from food?

Answer 56

chemical enegry

Question 57

law of consevrtaion of enegry means that the toatl energy remains ____

Answer 57

constant