science chapter 2.1.2

Question 1

a push or a pull on an object

Answer 1

force

Question 2

a push or a pull on an object by another that is touching it

Answer 2

contact force

Question 3

a force that one can apply to another object without touching it

Answer 3

noncontact force

Question 4

Name 3 types of noncontact forces

Answer 4

gravity, magnetic forces, and electric forces

Question 5

When using arrows to show forces, the longer the arrow, the…

Answer 5

stronger the force

Question 6

The SI unit for force

Answer 6

Newton (N)

Question 7

an attractive force that exists between all objects that have mass

Answer 7

gravity

Question 8

the amount of matter in an object

Answer 8

mass

Question 9

The unit used for measuring mass

Answer 9

kilograms (kg)

Question 10

Sir Isaac Newton discovered…

Answer 10

the law of universal gravitation

Question 11

states that all objects are attracted to each other by a gravitational force

Answer 11

the law of universal gravitation

Question 12

the strength of gravitational forces depends on…

Answer 12

the mass of each object and the distance between them

Question 13

when the mass between one or both of two objects increases, the…

Answer 13

gravitational force between them also increases

Question 14

The attraction between two objects decreases as…

Answer 14

the distance between the objects increases

Question 15

the gravitational force exerted on an object

Answer 15

weight

Question 16

weight is also measured in…

Answer 16

Newtons (N)

Question 17

An objects weight is ___________ to its mass

Answer 17

proportional

Question 18

When near earths surface, the weight of an object in newtons is about __________ its mass in kilograms

Answer 18

10 times

Question 19

Weight in space is _____ of what it was on earth

Answer 19

90%

Question 20

a force that resists the motion of two surfaces that are touching

Answer 20

friction

Question 21

prevents surfaces from sliding past each other

Answer 21

static friction

Question 22

opposes the motion of surfaces sliding past each other

Answer 22

sliding friction

Question 23

between a surface and a fluid-any material, like water or oil, that flows

Answer 23

fluid friction

Question 24

Friction is caused by….

Answer 24

bumps and ridges on surfaces or weak electric charges in objects

Question 25

decreases friction

Answer 25

lubricants

Question 26

less friction =

Answer 26

more sliding

Question 27

The combination of all forces acting on an object is the

Answer 27

net force

Question 28

forces acting on an object that combine and form a net force of zero

Answer 28

balanced forces

Question 29

forces acting on an object that combine and form a net force that is not zero

Answer 29

unbalanced forces

Question 30

according to Newton’s __________________, if the net force on an object is zero, the motion of the object does not change

Answer 30

Newton’s first law of motion

Question 31

the constant velocity reached when air resistance equals the force of gravity acting on a falling object

Answer 31

Terminal Velocity

Question 32

The tendency of an object to resist a change in its motion

Answer 32

inertia

Question 33

if there was no friction, object would…

Answer 33

continue moving at the constant force they are at because of inertia

Question 34

objects stop moving because

Answer 34

friction or another force acts on them