Science - Chpt 1 - Matter In Motion

Front 1

motion

Back 1

an object s change in position relative to a reference point

Front 2

speed

Back 2

the distance traveled divided by the time interval during which the motion occurred

Front 3

velocity

Back 3

the speed of an object in a particular direction

Front 4

acceleration

Back 4

the rate at which velocity changes over time; an object accelerates if its speed, direction, or both change

Front 5

force

Back 5

a push or a pull exerted on an object in order to change the motion of the object; force has size and direction

Front 6

newton

Back 6

the SI unit for force (symbol, N)

Front 7

net force

Back 7

the combination of all of the forces acting on an object
- forces in same direction added
- forces in opposite direction subtracted

Front 8

friction

Back 8

a force that opposes motion between two surfaces that are in contact

Front 9

gravity

Back 9

a force of attraction between objects that is due to their masses

Front 10

weight

Back 10

a measure of the gravitational force exerted on an object; its value can change with the location of the object in the universe

Front 11

mass

Back 11

a measure of the amount of matter in an object

Front 12

centripetal acceleration

Back 12

acceleration that occurs in a circle
example;
Ferris wheel
moon circling earth

Front 13

positive acceleration

Back 13

increase in velocity

Front 14

negative acceleration or deceleration

Back 14

decrease in velocity

Front 15

resultant velocity

Back 15

add two velocities that are in the same direction
ex: walking on a bus the same direction it is moving

Front 16

how is speed represented on a graph?

Back 16

distance vs time

Front 17

how is acceleration represented on a graph?

Back 17

velocity vs time

Front 18

how can an object accelerate?

Back 18

by changing speed, direction, or both

Front 19

balanced forces

Back 19

when the forces on an object produce a net force of 0N
- will not cause a change in motion in a moving object
- does not cause a non moving object to start moving

Front 20

unbalance forces

Back 20

net force is not 0N
- cause a change in motion
- need to make a nonmoving object move

Front 21

name two factors that determine the amount of friction between two objects

Back 21

the force pushing the surfaces together
how rough the surface is

Front 22

name two types of friction

Back 22

static and kinetic

Front 23

kinetic friction

Back 23

friction between moving surfaces

Front 24

static friction

Back 24

when force is applied to an object but it does not move.

Front 25

how does static friction become kinetic friction

Back 25

when enough force is applied to an object to overcome static friction

Front 26

ways to reduce friction

Back 26

lubricants (motor oil, wax and grease)
using wheels 9 rolling kinetic friction
smooth surfaces

Front 27

law of universal gravitation

Back 27

all objects in the universe attract each other through gravitational force. size of the force depends on the masses of the objects and the distance between the objects.

Front 28

why is it easier to pick up a cat than an elephant?

Back 28

the amount of gravity between a cat and earth is less than an elephant

Front 29

What is the difference between mass and weight

Back 29

weight changes when gravitational force changes.

Mass does not change

Front 30

Si unit for mass

Back 30

kilogram (kg)
grams (g)
milligrams (mg)