Physics 10 Flashcards
Uniform motion
when an object travels at the same speed in a straight line (hard to maintain)
Average speed formula
average speed= distance travelled/time elapsed OR V= d/t
distance formula (speed)
d= v x t
Time formula (speed)
t= d/v
Distance time graph/ position time graph horizontal line
a flat line indicates zero speed, the object is stationary
Steep line on a distance/position time graph
a steep line indicates a fast speed
Shallow line on a distance/ position time graph
a shallow line indicates a slow speed
Slope calculation for distance/ position time graph
slope= rise/run
=change in distance/ change in time
=df-di/tf-ti
=speed
Slope calculation for speed time graph
slope= rise/run
= change in speed/change in time
=Vf-Vi / tf-ti
=acceleration
Speed time graph line meaning : Horizontal line
zero slope- constant speed (no acceleration)
Speed time graph line meaning: upwards line
positive slope- speeding up
Speed time graph line meaning: downwards line
negative slope- slowing down
Calculation for area under the line on a speed time graph
Area = length x width
= (v) x (t)
= distance
Scalar
magnitude only, how much or how far
Scalar examples
Time, mass, measure
Vector
Magnitude and direction, indicated by arrow above symbol
Vector examples
displacement, velocity, acceleration, force
Distance
Scalar quantity, measurement of how far an object has travelled
distance = xm + xm
= xm
Displacement
Vector quantity, measurement of the change in distance and direction (must use direction in the calculation)
displacement = xm (east) + xm (west)
= xm
North and up is a _____ direction
positive
East and right is a _____ direction
positive
South and down is a _____ direction
negative
West and left is a ______ direction
negative
Velocity
Change is displacement over time, vector quantity
V= d/t (With arrows over “V” and “d”)
Formula for finding displacement (velocity)
d= V x t
Formula for finding time (velocity)
t= d/v
Acceleration is the change in _____ over time
velocity
Positive acceleration
- Positive magnitude and positive direction (speeding up going north, east, up, or right)
- Negative magnitude and negative motion (slowing down going south, west, down, or left)
Negative acceleration
- Negative magnitude and positive direction (slowing down going north, east, up or right)
- Positive magnitude and negative direction (speeding up going south, west, down or left)
Acceleration formula
a= v/t
a= vf-vi/t
acceleration= change in velocity
Find “t” for acceleration
t= vf-vi/a
Find “vf” for acceleration
Vf= (t x a) + Vi
Find “vi” for acceleration
vi= vf - (t x a)
Position time graph line of best fit will be a _____ curve
smooth
Speeding up on a position time graph is in the _____ direction
positive
Slowing down on a position time graph is in the _____ direction
negative
On a velocity- time graph positive slope=
positive acceleration
On a velocity - time graph, negative slope=
negative acceleration
On a velocity - time graph, area under the line determines
the displacement of the object
Area of a triangle formula
A = b x h/2
Area of a square/ rectangle
A= l x w
Inertia
The tendency to resist changes in motion
Force (and formula)
A push or pull on an object
Formula = F= ma
Work (and formula)
When a force moves an object through a distance
Formula = W= Fd
W= joules or newton metres
F= newtons
d= metres
What 3 conditions must be met for work to be done?
Movement, force, force and distance the objects travel in the same direction
Energy
The ability to do work, measured in joules, work done to an object is equal to the energy gained by the object
Formula= E= w
Evidence for presence of energy
- change in motion
- change in shape
-change in temperature
Light
from the sun and other light sources
Sound
sound released from vibrating object
Electrical
the work done by moving charges (ex. generator)
Thermal
Heat energy
Potential energy
stored energy ready to be released
Gravitational
lifting something up
Chemical
potential energy stored in the chemical bonds of compounds
Elastic
rubber band or string
Nuclear
potential energy stored in the nucleus of an atom
Kinetic
energy of moving object
Mechanical
the sum of the energy of the motion and position
Solar energy
sun energy
Types of potential energy
- gravitational
- chemical
- elastic
- mechanical
Gravitational potential energy formula
Ep(grav) = mgh
Find “m” in gravitational potential energy formula
m= Ep/gh
Find “h” in gravitational potential energy formula
h= Ep/mg
Ep elastic energy formula
Ep= W
OR
Ep = Fd
Kinetic energy formula
Ek= 1/2 mv(squared)
OR
k mv(squared) / 2
Find “m” in Ek formula
m= 2Ek / v (squared)
Find “v” in Ek formula
v= square root 2Ek / m
Mechanical Energy
the energy due to motion and position of an object
Em formula
Em= Ep + Ek
Find Ep in Em formula
Ep= Em- Ek
Find Ek in Em formula
Ek= Em - Ep
Law of conservation of energy
- The total amount of energy remain constant as energy is converted from one form to another
- Total mechanical energy always remain constant
- Energy is always conserved
1st law of thermodynamics
- Energy is never created or destroyed
- The total energy, including heat in a system and its surroundings remains constant
2nd law of thermodynamics
- During some energy conversions, some useful energy is lost as thermal energy in most cases
- Heat flows from matter at a higher energy level to matter at a lower energy level
Efficiency formula
Eff= useful energy output / total energy input x 100
