exam revision

Question 1

what is inertia ?

Answer 1

The tendency of a body to resist a change in motion or rest.

Question 2

crumple zones

Answer 2

The area of a vehicle that is designed to crush or crumple upon impact. Often located in the front of a vehicle.

Question 3

velocity

Answer 3

the speed of something in a given direction

Question 4

what is a contact force & examples

Answer 4

Contact forces are forces that require direct physical contact between two objects. Examples of contact forces include friction, tension, and air resistance.

Question 5

what is a non contact force & examples

Answer 5

Gravitational force, Electrostatic force, Magnetic forces. They are non-contact forces because they can influence the objects without being in contact.

Question 6

what is air resistance

Answer 6

The force acting on an object that is moving through air flowing in the opposite direction.

Question 7

what is gravity

Answer 7

A force which tries to pull two objects toward each other.

Question 8

what is a force

Answer 8

a push, pull or twist

Question 9

what is friction

Answer 9

The force felt between two surfaces when one attempts to slide against the other — whether they are moving.

Question 10

what is a mixture

Answer 10

A physical combination of two or more substances

Question 11

what is a solution

Answer 11

A type of mixture involving two or more substances.

Question 12

what is a colloid

Answer 12

A mixture of particles smaller than those found in a suspension but bigger than those found in a solute

Question 13

what is a suspension

Answer 13

mixture where solid particles do not dissolve in a liquid solution

Question 14

what is a sediment

Answer 14

When the soluble substance falls to the bottom of the mixture

Question 15

what is an emulsion

Answer 15

A liquid dispersed in a liquid eg. Milk

Question 16

what does it mean when a solution is saturated

Answer 16

A physical or chemical situation where a system can take no more of a substance.

Question 17

what does it mean when a solution it concentrated

Answer 17

The amount of a substance, such as a salt, that is in a certain amount of tissue or liquid, such as blood.

Question 18

what does it mean when a solution is diluted

Answer 18

The process of decreasing the concentration of a solute in a solution, usually simply by mixing with more solvent.

Question 19

what is density

Answer 19

how tightly a material is packed together

Question 20

what is qualitative & example

Answer 20

using words to describe your observations eg. big dog

Question 21

what is quantitive & example

Answer 21

using numbers to describe your observations eg. 24 ducks

Question 22

what is an inference & when do u use it

Answer 22

An inference is when you draw a conclusion from the evidence/experiment you have conducted. You would write an inference in your conclusion.

Question 23

what is terminal velocity

Answer 23

is the maximum speed attainable by an object as it falls through a fluid

Question 24

list one way to reduce friction

Answer 24

by greasing/oiling one of the surfaces touching each other

Question 25

list one way to increase friction

Answer 25

by applying more force to an object, making the 2 surfaces push harder against one another

Question 26

what is a speed multiplier

Answer 26

Speed multipliers are devices that increase the speed of, or distance travelled by, an object.

Question 27

what is a force multiplier

Answer 27

something that multiples the effort and force put in