Science chpt 3

Question 1

What are the 9 types of energy?

Answer 1

• Eletric energy; movement of electrons
  -Elastic; stored du to compression on tension
  -Thermal energy; movement of particles
  -Radiation energy; Energy controlled in and transported by electromagnetic waves
  -Chemical energy; energy stored in chemical bonds
  -Wind energy; the movement of wind
  -Sound energy; sound waves
  -Hydraulic; movement of water
  -Nuclear; energy stored in the nucleus

Question 2

What are the units of energy?

Answer 2

Joules

Question 3

What is a joule?

Answer 3

-One joule corresponds to the energy required to move an object with the force of one newton, over a distance of 1m

Question 4

What is the formula for energy?

Answer 4

1J = 1N x 1m

Question 5

What is the law of conservation of energy?

Answer 5

-states that energy cannot be created it can only be transmitted or transformed. The total amount of energy stays constant

Question 6

What is an energy transfer?

Answer 6

the movement of energy from one place to another
ex; electricity moving in a wire

Question 7

What is an energy transformation?

Answer 7

the changing of energy from one form to another

Question 8

What is energy efficiency?

Answer 8

the percentage of energy consumed by a machine or systems that is transformed into useful energy

Question 9

What is the energy efficiency formula?

Answer 9

EE = (amount of useful energy/amount of energy consumed) x 100

Question 10

What are factors can affect thermal energy?

Answer 10

1) number of particles
-increase=increase in energy
-decrease= decrease in energy
2) Temperature
-Increase in temperature = increase in energy

Question 10

What is the difference between heat and temperature?

Answer 10

-heat is the transfer of thermal
energy between 2 environments with different temperatures
-Temperature; the measure of agitation of particles in the substance

Question 11

What is motion?

Answer 11

object changes place in a respected time

Question 11

what is speed?

Answer 11

the distance traveled per unit of time

Question 12

What is velocity?

Answer 12

the speed in a given direction

Question 13

What is a force?

Answer 13

an action that can change the motion of an object or deform an object by pulling or pushing

Question 14

How to represent force?

Answer 14

1) the horizontal force of action (dotted line)
2) the direction of application of force (arrowhead)
3) Magnitude of force (length of arrowhead or number)
4) Point of application (where arrow starts)

Question 15

What is the unit of force?

Answer 15

Newtons (N)

Question 16

Formula for force?

Answer 16

1N = 1kg x 1ms

Question 17

How can velocity change the motion of an object?

Answer 17

-by giving velocity to a stationary object or by increasing velocity of an object already in motion
- By reducing velocity of an object either by slowing it down or stopping (applied in the opposite direction)

Question 18

What is acceleration?

Answer 18

force applied in the direction of motion

Question 19

What are the types of forces?

Answer 19

-electromagnetic forces
-friction
-gravitational force

Question 20

What is electromagnetic force?

Answer 20

force of attraction or repulsion between two objects with an electric charge or magnetic poles

Question 21

what is friction?

Answer 21

the force that prevents two objects from slipping when they come into contact

Question 22

What does friction depend on?

Answer 22

1) the nature of the surface
2) The intensity of pressure on each surface
3) strong and weak nuclear forces

Question 23

What is gravitational force?

Answer 23

a force of attraction between all objects

Question 24

What affects gravitational force?

Answer 24

1) mass; higher the mass higher the attraction 2) distance; greater distance greater attraction

Question 25

what is mass?

Answer 25

- the amount of matter in an object ( doesn't depends on location)

Question 26

What is weight?

Answer 26

-the measure of gravitational force acting on an object (depends on location)

Question 27

Formula for weight?

Answer 27

w=mg w=weight m=mass g= gravitational force

Question 28

What is resultant force?

Answer 28

a virtual force whose action is equal to all the forces applied

Question 29

How to calculate resultant force?

Answer 29

two are applied you take the different from the biggest minus the smaller one

Question 30

What is an equibrillum?

Answer 30

-achieved when the restored force is zero resultant force=net force

Question 31

what is a fluid?

Answer 31

a substance that has the ability to flow and take shape of the container

Question 32

what is a compressible fluid?

Answer 32

- a fluid in while the volume can change (gas)

Question 33

what is an incompressible fluid?

Answer 33

- a fluid in which the volume cannot change

Question 34

What is pressure?

Answer 34

the amount of force applied perpendicularly to an object per unit of surface area

Question 35

what is the formula for pressure?

Answer 35

p=f/a p=pressure f=force a= surface area

Question 36

What is the unit for force?

Answer 36

pascals (pa)

Question 37

What are the 2 things pressure in a liquid depend on?

Answer 37

1) depth; depth increase = pressure increase, decrease = decrease 2) Density; density increase = pressure increase decrease =decrease

Question 38

what are two things pressure in a gas depend on?

Answer 38

1) collisions between particles -3 things that depends on a) temperature; increase=increase pressure b) volume; less space = more collisions -> volume dec= pressure inc

Question 39

What does pascals principle state?

Answer 39

when pressure is applied to a place it get transmitted throughout the whole system?

Question 40

What does archemidies principle state?

Answer 40

An object in water is subjected to a force equal to the weight of the displaced fluid