Topic 1 Movement and Force

Question 1

what is 1-dimensional motion?

Answer 1

the movement of a particle/subject along an x-axis

Question 2

what is 2-dimensional motion?

Answer 2

the movement of a particle/object along an x and y-axis

Question 3

define distance.

Answer 3

-the length the object has travelled in total.
-has magnitude only (is a scalar quantity)
-measured in meters (m)

Question 4

define displacement.

Answer 4

-the change in an object’s position from it’s origin.
-has magnitude and direction (is a vector quantity)
-the magnitude is measured in meters (m)
-symbol is Δx

Question 5

how is the magnitude of displacement represented?

Answer 5

the length measured along a straight line between the initial (xi) and final (xf) position of an object

Question 6

define elapsed time

Answer 6

-the time between the initial and final time.
-symbol is Δt

Question 7

initial position and final symbol

Answer 7

initial position= xi (i is subscript)
final position= xf (f is subscript)

Question 8

initial time and final time symbol

Answer 8

initial time= ti (i is subscript)
final position= tf (f is subscript)

Question 9

particle definition

Answer 9

an object that can be represented as a mass at a single point in space

Question 10

the particle model of motion

Answer 10

a model that describes the arrangement and movement of particles in a substance

Question 11

define speed

Answer 11

-the distance an object has covered relative to time
-is a scalar quantity
-(speed= distance/Δt)

Question 12

define instantaneous speed

Answer 12

the speed at any particular moment

Question 13

define velocity

Answer 13

-a vector quantity that describes how fast and in what direction an object is going.
-(velocity= change in position/change in time= Δx/Δt= xf-xi/tf-ti)

Question 14

characteristics of a position vs time graph

Answer 14

-time is on x-axis
-position is on y-axis
-continuous curve shows the object’s position at all instances in time.

Question 15

characteristics of a velocity vs time graph

Answer 15

-time is on x-axis
-velocity is on y-axis
-position vs time graphs can be translated into this using Δx/Δt

Question 16

characteristics of acceleration vs time graph

Answer 16

-time is on x-axis
-acceleration is on y-axis
-

Question 17

how can the velocity of an object be changed

Answer 17

-by changing it’s speed
-by changing it’s direction
-by changing it’s speed and direction

Question 18

define acceleration

Answer 18

-how much an object’s velocity changes in a given amount of time.
-acceleration (a)=Δv/Δt=vf-vi/tf-ti

Question 19

what is this object’s direction and velocity?

Answer 19

the object is moving right (vx>0) and speeding up

Question 20

what is this object’s direction and velocity? (velocity vs time graph)

Answer 20

the object is moving right (vx>0) and slowing down

Question 21

what is this object’s direction and velocity? (velocity vs time graph)

Answer 21

the object is moving left (vx<0) and speeding up

Question 22

what is this object’s direction and velocity? (velocity vs time graph)

Answer 22

the object is moving left (vx<0) and slowing down

Question 23

define newton’s first law of of motion/law of inertia

Answer 23

-with no outside forces a stationary object will never move, and a moving object will never stop.

Question 24

define inertia

Answer 24

resistance to changes in velocity

Question 25

define a force

Answer 25

-a force is a specific action acting on an object (push/pull).
-force doesn’t exist in isolation from the object it acts on.
-a force is a vector quantity (direction and magnitude)

Question 26

what is a contact force?

Answer 26

-contact forces act on an object by directly coming into contact with it.
-the force lasts as long as the agent and object are in contact. (e.g. tension force, friction, spring force)

Question 27

what is a long-range force/non-contact force

Answer 27

-act on an object without physical contact (e.g. magnetic force, weight force, electrical force)

Question 28

what is weight force

Answer 28

-the gravitational pull on an object
-agent= entire earth pulling on an object.
-the weight vector is always vertically downward.
-symbol= w

Question 29

what is spring force/elastic force

Answer 29

-a spring can push when compressed or pull when stretched
-symbol=F/Fsp (sp is subscript)

Question 30

what is tension force

Answer 30

-occurs when a string/rope/wire pulls on an object.
-the tension force can only pull in the direction of the string/rope/wire
-symbol= T

Question 31

what is normal force

Answer 31

-the force exerted by a surface (the agent) against an object pressing against the surface.
-the surface exerts a force perpendicular to itself.

Question 32

what is friction

Answer 32

-a type of force
-like normal force, the agent is the surface, but friction is parallel to the surface.
-there are two kinds of friction, static friction and kinetic friction.

Question 33

what is static friction

Answer 33

-a sub-type of friction and type of force
-the force that keeps an object stuck on a surface.
-the force points in the direction opposite to where the object would move if there was no friction
-symbol= fs (s as subscript)

Question 34

what is kinetic friction

Answer 34

-a sub-type of friction and type of force
-acts as an object slides against a surface
-it opposes the motion and the force points in the direction opposite to the motion of the object.
-symbol= fk (k as subscript)

Question 35

what is drag

Answer 35

-a type of force
-opposes motion through fluids (gases and liquids)
-drag points in the opposite direction of motion
-symbol= D

Question 36

what is electrical force

Answer 36

-most objects are electrically neutral/have no net electrical charge
-when an object has a net electrical charge, there will be a force between the charged object and other objects
-electrical forces can be attractive or repulsive depending on the type of electrical charge.

Question 37

list the types of forces

Answer 37

-weight force
-spring force/elastic force
-tension force
-normal force
-friction (kinetic and static)
-drag
-electrical force

Question 38

mass-force relationship

Answer 38

-objects with more mass require more force to change velocity than lighter objects. the inertia of an object is gratified by it’s mass.

Question 39

what is mass

Answer 39

-mass is a property of objects
-mass is a scalar quantity (magnitude) and can never be 0
-units are measured in (kg)
-an object’s mass doesn’t change according to location (mass of an object is the same on earth as it is on mars)
-mass≠weight

Question 40

what is Newton’s second law of motion

Answer 40

-the sum of all forces on an object is proportional to the mass of the object and the force exerted on it.
-the sum of all forces=mass x acceleration (ΣF=m x a)

Question 41

what is the sum of all forces

Answer 41

-all forces being applied on an object.
-symbol= ΣF
-AKA net force/resultant force
-m=(kg), a= (m/s2) so ΣF=(kg x m/s2)

Question 42

what is the newton

Answer 42

-the newton is the SI unit of force.
-1N= (1kg x m/s*2)

Question 43

what does it mean if ΣF= 0?

Answer 43

-acceleration =0
-there is no increase/decrease in velocity or change in direction

Question 44

what does it mean if ΣF≠ 0?

Answer 44

-acceleration >0
-there is an increase/decrease in velocity or change in direction.