Physics Unit 1

constant velocity, motion and forces

What is a Vector

Quantity with direction and Magnitude

what is a scalar

Quantity with magnitude only

what is Magnitude

the size, amount or strength of something

when drawing a Vector what does a longer aarow mean

larger magnitude

What is a force

A push or pull

• measured in Newtons

• symbol : F

what is one thing every source has

an agent

what is an agent

the source or cause of an action/ force

Contact force

the agent is touching the system (contact)

field force:

the agent can act from a distance using a force field

what is weight

the force of gravity acting on an object

• unit (N)

• symbol (Fg)

if mass is at rest all forces acting on the mass must be _ _ _ _ _ _ _ _

balanced

what happens in a proportional relationship

when x value doubles y value doubles

what happens in an exponential relationship

when x value doubles y value quadruples

inverse relationship

one variable increases the other decreases, when x value doubles y value halves

what is mass

the measure of the amount of stuff

• symbol (M)

• measured in Kg

Gravitational field value

tells you how strong gravity is at a particular point

(the Fg acting on 1kg of mass)

• symbol (G)

• units: N/Kg

• G= -10n/kg

what is the relationship between mass and weight

mass = how much matter is in an object

weight = the force of gravity pulling on that mass

What is newtons first law

an object in motion stays in motion, an object at rest stays at rest unless acted upon by an external force (Inertia)

Equillibrium

when all forces are balanced and an object stays in its current state of motion due to Inertia

Types of forces:

Weight (Fg)

force of gravity

Types of forces:

normal force (Fn)

force exerted by a surface on an object in contact with it

(ex: when something like a book is placed on a table, gravity pulls it down, it doesnt fall down cause table pushed back up on it w equal force)

Types of forces:

Force of friction (Ff)

force opposing the motion of an object when it is in contact w another source

Types of forces:

Force of tension (Ft)

force from a rope or swing (the pulling force inside the rope)

Types of forces:

force applied (Fa)

Force of one object pushing another its a push or pull you apply to an object

What is position

how far away an object is from a reference point

Distance: D

sum of all the travel done by an object

Displacement (delta X)

Final/ total position change of an object

position time graphs

• The slope of the graph is velocity

• steeper slope = faster speed

• positive slope = forward up or right

• negative slope = backward down or to the left

• flat line = 0 at rest

Velocity time graphs at CV

• horizontal line = CV

• close to X axis = slow

• far from X axis = Fast

• positive values = above T axis

• negative values: Below T axis

Directly proportional

y= k X

if x value inc y inc by same value

delta X= v t

inversley proportional

y=k/x

if x inc y dec by same factor

v= delta x/ t