Forces and Motion Chapter 1 Flashcards Preview

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Flashcards in Forces and Motion Chapter 1 Deck (26):
1

define motion

an objects change in position relative to a reference point

2

how can you describe the direction of an objects motion

using a reference direction

3

define speed

distance traveled divided by the time during which the motion occured

4

give an example of metric and english units used to measure speed

metric- meters/second english- miles/hour

5

define velocity

the speed of an object in a particular direction

6

how is velocity different from speed?

it's the same as speed except velocity uses a reference direction

7

what can be said about the velocity of an object that is in circular motion?

an object traveling in a circular motion is always changing direction, so it's accelerating (centripetal acceleration)

8

define force and give the unit

a push or a pull exerted on an object that changes the motion, expressed in newtons

9

what is net force?

combination of all the forces acting on an onject

10

how do you calculate net force when the forces are in the opposite direction?

add them together

11

how do you calculate net force when the forces are in the opposite direction?

subtract the smaller force from the bigger one

12

what is the net force when the forces are balanced?

0 newtons

13

what occurs when forces are balanced?

will not cause a change in motion, will not cause a non-moving object to start moving

14

what occurs when forces are unbalanced

produce a change in motion, will cause motionless object to start moving

15

define friction

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

16

how does force affect friction?

adding more force increases friction

17

does a rough or smooth surface cause friction and why?

rougher surfaces have more friction because they have more hill/valleys in the surface that can come into closer contact

18

what effect does surface area have on friction?

none

19

what is the different between kinetic and static friction?

kinetic is friction between moving objects, static is when force is applied but does cause the object to move

20

name examples of how friction can be harmful

-cause car parts part to heat up/wear down
-cause holes in socks/jeans

21

name examples of how friction can be helpful

-allows pencil to leave a mark
-you would slip and fall w/out friction
-helps brakes stop a car

22

how can you decrease friction?

-use lubricants
-make surfaces smoother
-switch from sliding kinetic friction to rolling kinetic friction

23

how can you increase friction?

-make surfaces rougher
-increase force pushing surfaces together

24

define gravity

force of attraction between objects what is due to their masses

25

what two factors determine gravitational force

mass and distance

26

define mass and weight

mass- amount of matter in an object
weight-measure of gravitational force exerted on an object