Science WA2

Question 1

What is speed?

Answer 1

Speed is a measure of how fact an object moves and is defined as the distance travelled per unit time

Question 2

What a force do?

Answer 2

Make a stationary object move
Stop a moving object
Make a moving object speed up or slow down
Change the direction of a moving object
Change the shape and size of an object
Create a turning effect to make an object turn or move

Question 3

SI Unit for forces

Answer 3

Newton (N)

Question 4

What can forces be measured by?

Answer 4

by a force meter e.g. spring balance

Question 5

What are the types of forces and definitions?

Answer 5

Non-contact force
Force that acts between objects that are not touching each other
Contact Force
Force that sits between objects that are touching each other

Question 6

What is gravitational force?

Answer 6

Gravitational force is a force that exists between objects that have mass

Question 7

What is the formula of gravitational force

Answer 7

w = mg w:weigh(in N) m:mass(in kg) g: gravitational field strength (in N/kg)

Question 8

As mass increased, weight on earths surface…

Answer 8

increases

Question 9

Mass vs weight

Answer 9

Mass is the measure of the amount of matter in an object and depends on the number of particles used to make an object

Weight is the meausre of gravitational force acting on a object
depends on both mass of object and gravitational field strength at location

Question 10

Si Unit of mass

Answer 10

kg

Question 11

SI Unit of weight

Answer 11

newton(N)

Question 12

mass measured by..

Answer 12

electronic balance and beam balance

Question 13

weight measured by…

Answer 13

extension spring balance, compression spring balance

Question 14

What is magnetic force

Answer 14

exerts a non contact force known as a magnetic force

Question 15

What is frictional force

Answer 15

Friction is a force which opposes the movement of an object

Question 16

When does friction act?

Answer 16

whenever one surface rubs against another surface

Question 17

What is air resistance

Answer 17

Air resistance is the frictional force experienced by a moving object in the air

Question 18

Application of friction

Answer 18

prevents us from slipping when we walk
prevents objects from slipping from our hands
allows us to light a matchstick

Question 19

bad things about friction

Answer 19

causes surfaces to heat up
can wear down objects
can slow down movement

Question 20

how to overcome friction

Answer 20

applylubraicants between surfaces
use of wheels and ball bearings
make sirfaces smoother
streamlining

Question 21

What is the state of motion

Answer 21

State of motion simply desciribes how an object is moving

Question 22

when forces are balance, resultant force is…

Answer 22

zero. objects will continue to be at res tor move with constant speed in a striaght line

Question 23

effects of resultant force

Answer 23

start a body moving
stop a moving body
change the speed of the body
change direction of body

Question 24

Pressure

Answer 24

defined as the force applied perpendicular to the surface of an object per unit area

Question 25

formula of pressure

Answer 25

force/contact area

Question 26

SI unit of pressure

Answer 26

Pascal (Pa) or newton per square metre (N/msquared)

Question 27

Factors affecting pressure

Answer 27

Area of contact, force

Question 28

fluid pressure

Answer 28

pressure in a liquid increases with the depth and density at the liquid with gravitational field strength

Question 29

what is the turning effect of a force called

Answer 29

pivot

Question 30

for turning effect to increase

Answer 30

force applied at perpendicular distance furthest away from the pivot

Question 31

What is energy

Answer 31

energy is the ability to do work

Question 32

si unit of energy

Answer 32

joule (J)

Question 33

what is GPE

Answer 33

energy stored due to an object's height from a reference point in a gravity field

Question 34

factors affecting GPE

Answer 34

mass of object and vertical height of the object above its reference point and gravitational field strength acting on object

Question 35

principle of conservation of energy

Answer 35

energy cannot be created or destroyed energy can only be converted from one form to another

Question 36

difference when negligible air resistance

Answer 36

w air resistance + TE when gg up rate of energy production goes down and when gg down rate of energy production goes up

Question 37

what is work done

Answer 37

product of a force and the distance moved in the direction of the force

Question 38

formula of work done

Answer 38

force * distance moved in the directions of the force

Question 39

si unit of work done

Answer 39

joule (J)

Question 40

there is NO work done when:

Answer 40

does not move even when force is applied moves at a constant speed when there is no force acting on it moves perpendicular (at a right angle) to the force at a constant speed application meterorite

Question 41

renewable energy

Answer 41

energy that is replenished or resupplied faster than being used up

Question 42

non renewable energy

Answer 42

energy that is used up faster than it can be replenished or resupplied

Question 43

non renewable forms of energy

Answer 43

fossil fuels, nuclear energy

Question 44

renewable forms of energy

Answer 44

biofuels, wind, hydropower, geothermal power, solar power

Question 45

fossil fuels adv/disad

Answer 45

fossil fuels are relatively cheap does not depend on env. factors non renewable will pollute the env as it contributes to greenhouse gases

Question 46

nuclear energy adv/disad

Answer 46

clean energy with no greenhouse gas emission non renewable, expensive, time-consuming to build requires a lot of space and land

Question 47

biofuels adv/disad

Answer 47

renewable can be produced from the recycling of food waste requires a lot of space and land lead to deforestation and habitat loss burning of biofuels releases greenhouse gases

Question 48

wind adv/disad

Answer 48

clean, sustainable and abundant cost effective, nofuel costs variabke energy source turbines can be loud and negatively impact local wildlife

Question 49

hydropwer adv.disad

Answer 49

renewable source of energy no pollution as no burning of fossil fuels affects wildlife in the process of construction hydro electricity dams flood farms and push people from their homes

Question 50

Geothermal power adv/disad

Answer 50

renewable energy resource no harmful polluting most parts of the world do not have suitable areas where it can be exploited

Question 51

solar power ad/disad

Answer 51

renewable energy source no harmful polluting has high initial cost requires a lot of space weather dependant