science forces and speed for test

Question 1

what is a force?

Answer 1

a push or a pull

Question 2

what does friction do?

Answer 2

it always opposes motion

Question 3

what does weight do?

Answer 3

it pulls things downwards

Question 4

what does air resistance (drag) do?

Answer 4

it acts against anything moving through the air

Question 5

what does upthrust do?

Answer 5

it keeps things afloat

Question 6

what force goes against weight?

Answer 6

reaction force

Question 7

what does a force with a vector quantity mean?

Answer 7

that it has a size and a direction

Question 8

how do you draw forces on an object?

Answer 8

with arrows

Question 9

what must these arrows have/do?

Answer 9

they must start touching the object and come away from it in the direction the force is going.

Question 10

what is happening to the object if the arrows are the same size?

Answer 10

it is either staying still or travelling at a constant speed

Question 11

what is the object doing if the arrows are of DIFFERENT sizes?

Answer 11

it is either changing shape, direction or speed

Question 12

what is the difference between the 2 forces called?

Answer 12

the resultant force

Question 13

true or false, weight is a force.

Answer 13

true

Question 14

what does it measure?

Answer 14

the effect gravity is having on an object

Question 15

what is weight measured in?

Answer 15

newtons (with a newton meter)

Question 16

what is mass a measurement of?

Answer 16

how much of something there is

Question 17

what is the earth’s gravitational field strength?

Answer 17

10 newtons per kilogram

Question 18

what is the formula for weight?

Answer 18

mass x gravitation force

Question 19

what is the formula for mass?

Answer 19

weight/gravitational force

Question 20

what is the formula for gravitational force?

Answer 20

weight/mass

Question 21

what is weight on earth?

Answer 21

mass x 10

Question 22

what is mass on the moon?

Answer 22

mass x 4

Question 23

when can friction be useful? (2)

Answer 23

brakes, starting a fire

Question 24

when can friction NOT be useful?

Answer 24

air resistance, wanting to go faster

Question 25

what are the 3 characteristics of a streamlined shape?

Answer 25

rounded head with a slowly tapering tail, a smooth shape with no projections

Question 26

what are 2 ways to reduce friction?

Answer 26

lubrication, streamlining

Question 27

what is the formula for density?

Answer 27

mass of object/ volume of object

Question 28

what is the density of water?

Answer 28

1.0

Question 29

what is the density of oil?

Answer 29

0.9

Question 30

true or false- oil will always float on water- why/why not?

Answer 30

true because oil has a less density than water

Question 31

how do you find the volume of a regular object?

Answer 31

length x width x height

Question 32

how do you find the volume of a irregular object?

Answer 32

putting a set amount of water into a measuring jug, putting the object in, taking it out and seeing how much water was displaced (taken out)

Question 33

true or false- the reaction force is perpendicular

Answer 33

true