forces revision y7

Question 1

what force is keeping you on the earth

Answer 1

weight

Question 2

what forces are active on an accelerating car

Answer 2

friction air resistance thrust weight reaction

Question 3

what is mass measured in

Answer 3

kilograms

Question 4

what formula can you use to find out on objects weight

Answer 4

mass times by gravitational field strength

Question 5

what is weight measured in

Answer 5

newtons

Question 6

what is an independent variable

Answer 6

the thing we change

Question 7

what is a dependent variable

Answer 7

the thing we measure

Question 8

what is a controlled variable

Answer 8

the thing(s) we make the same

Question 9

what is the formula used to figure out the density

Answer 9

mass divided by volume

Question 10

if an object has a lower density then water what will it do?

Answer 10

it will float

Question 11

different liquids provide different amounts of upthrust force because

Answer 11

of their density

Question 12

what makes an aerodynamic shape

Answer 12

a rounded front a slowly tapering tail and a smooth shape with no projections

Question 13

what does friction always oppose

Answer 13

motion

Question 14

how can you find the average speed of a thing

Answer 14

by dividing the total distance by the total time

Question 15

what is tension

Answer 15

a stretching force

Question 16

what is the difference between mass and weight

Answer 16

mass is measured in kilograms while weight is measured in newtons

Question 17

when does friction occur

Answer 17

when two surfaces rub together

Question 18

what are some cases where friction is useful

Answer 18

brakes on a car lighting a match and strings on a violin

Question 19

what are some cases where friction is not useful

Answer 19

friction burn hinges on a door and air resistance when trying to move fast

Question 20

what is speed measured in

Answer 20

seconds minutes or hours