Physics - Ch. 8/9 (Yr 10) Flashcards
What is distance and what is it’s standard unit (SI) of measurement?
How far an object travels.
Standard Unit —> Metres (m)
What is ‘displacement’ and what is it’s standard unit (SI) of measurment?
How far an object is from the starting point.
Standard Unit —> Metres (m)
What is a ‘Scalar Quantity’?
Only has size/magnitude.
NO direction
—> Distance, Speed
What is a ‘Vector Quantity’?
Has size and direction.
—> Displacement, Velocity, Acceleration, Momentum, Net force
Position Time Graph musts:
—> What is the X axis always labeled as?
—> What is the Y axis always labeled as?
X axis: ‘Time’
Y axis: ‘Position’
If there is an upward slanted line on a position graph ABOVE the (0,0) line what does it mean?
Walking in a direction, for example North.
If there is an downward slanted line on a position graph BELOW the (0,0) line what does it mean?
Walking in the opposite direction, for example South.
If there is an straight consistent line on a position graph what does it mean?
There is a stop for however many seconds the line lasts for.
What is ‘Velocity’ and what is its standard unit (SI) of measurement?
The measuring of speed in a specific direction.
Standard unit —> Metres per second (m/s) and/or Kilometres per hour (Km/h)
What is ‘speed’ and what is its standard unit (SI) of measurement?
The distance traveled per unit of time.
Standard unit —> metres per second (m/s)
Formula for ‘Average Speed’?
Sav = d/t
d=Sav*t
t=d/Sav
Triangle: d on the top, and Sav with t on the bottom.
Sav= average speed, d = total distance, t = total time
Formula for ‘Average Velocity’?
Vav = d/t
d=Vav*t
t=d/Vav
Triangle: d on the top, and Vav with t on the bottom.
Vav= average Velocity, d = total displacement, t = total time
What does it mean when a line is slanted upwards in a Velocity/Speed time graph ABOVE (0,0)?
Increasing in a direction, for example North.
What does it mean when a line is slanted downwards in a Velocity/Speed time graph BELOW (0,0)?
Increasing in the opposite direction, for example South.
What does it mean when a line consistently straight in a Velocity/Speed time graph?
Moving at a constant speed/velocity.
Speed/Velocity time graph musts:
—> what is the X axis labeled as?
—> what is the Y axis labeled as?
X axis: Speed/Velocity
Y axis: Time
What does the area under a Velocity/speed graph determine?
What area formulas do you typically use?
It determines the distance traveled in that time.
Area of triangle: (bh)/2
Rectangle: bh
What does very spread out dots on ticker tape mean?
Fast
What does very close together dots on ticker tape mean?
Slow.
What does close dots that gradually become more spread out on ticker tape mean?
Slow getting faster.
What is ‘Acceleration’ and what is its standard unit (SI) of measurement?
How fast an object changes its velocity. (Rate)
Standard unit —> metres per second squared (m/s^2)
Formula for ‘Acceleration’?
a= (final velocity - start velocity) / (final time - start time)
Change in time = (final velocity - start velocity) / a
Change in velocity = (final time - start time) * a
Triangle: Triangle V at top, a and triangle t next to each other on bottom.
Triangle V= Change in Velocity, triangle t = change in time, a = acceleration.
What does an upwards slanted line indicate about the acceleration on a graph?
Constant positive acceleration.
What does an straight line indicate about the acceleration on a graph?
Zero acceleration, constant speed.
What does an downwards slanted line indicate about the acceleration on a graph?
Constant negative deceleration.
What is the first Newton law?
An objects motion only changes if another force acts upon it.
‘An object remains at rest or in constant motion in a straight line unless acted on by a net unbalanced force’ - Newton
What does Inertia refer to?
The tendency of an object to resist changes in its motion while either at rest or in constant motion.
What is ‘Net force’ and what’s its standard unit (SI) of measurement?
The vector sum of all the forces acting on an object; known as the resultant force.
Standard unit —> N
Formula for ‘Net force’?
fnet = m*a
m=fnet/a
a=fnet/m
fnet = net force, a = acceleration (m/s^2), m = mass (kg)
How does force affect acceleration? (2 points to answer)
If net force acts in the same way of the movement, increase acceleration.
If net force acts in opposite way of movement, deceleration.
What is the second Newton law?
The mass of an object affects the amount of force an object needs to stop even if the acceleration is the same.
‘The acceleration of an object is directly related to the magnitude & direction of the net force acting on the object, and inversely related to the mass of the object (fnet=m*a)’ -Newton
What is the third newtons law?
‘For every action, there is an equal and opposite reaction.
Action—>Reaction
What is a ‘reaction’ force?
The force acting in the opposite direction to an initial force.
eg. Insect hits windscreen (action: hitting the screen, reaction: bouncing off the screen)
What is the ‘law of conservation of momentum’?
‘In an isolated system, the total momentum does not change during collision’
What is ‘momentum’ and what is its standard unit (SI) of measurement?
The product of an object’s mass and velocity.
Standard unit —> Kg m/s
If an object is faster than its momentum is….
More
If an object has more mass than its momentum is……
More
Formula of momentum?
P=mxv
m=p/v
V=p/m
Triangle: P is at the top of the triangle, m and v are next to each other on the bottom.
P = Momentum, m= Mass, v=Velocity
How does the final momentum of an object change from the initial momentum. (*if it changes)
Initial momentum is equal to final momentum of all objects after.
What is ‘work’ energy? What is its standard unit?
The object is moved by a force.
Uses the unit joules (j)
The larger the force, the …… work done. (Fill in gap)
Greater
The longer the distance over which a force acts, the ……. the work done. (Fill in gap)
Greater
The formula of work energy?
W =f*d
d= w/f
F= w/d
Triangle: w is at top, d and f are next to each other at the bottom.
W= work, f = force, d= distance
What type of quantity is work energy?
Scalar
What do work and energy have in common?
Work measures how much energy has been transferred from one object to another.
Formula for kinetic energy?
KE=1/2 * m * V^2
m= (KE2) / V^2
V^2= (KEm) / 2
KE= kinetic energy, m= mass, v= speed
Larger the object mass, the ….. the kinetic energy. (Fill in gap)
Greater
Faster the object travels, the …. the kinetic energy. (Fill in gap)
Greater
Formula for gravitational potential energy?
GPE = mgh
GPE= Gravitational potential energy, m = mass, g= gravity (10m/s^2), h = height
The larger the mass and height, the …. gravitational potential energy the object gains.
More
Formula for elastic potential energy?
EPE = 1/2 * K * x^2
K= spring constant, x = compression/extensions, EPE = elastic potential energy
All energy uses the standard unit (SI) measurement…
joules (j)
Energy that is stored in deformed or bent out of shape elastic materials is known as?
Elastic potential energy
What is kinetic energy?
The energy possessed by moving objects
What is gravitational potential energy?
Energy possessed by an object raised to a height in a gravitational field.
What is elastic potential energy?
Energy possessed by stretched/compressed objects.
What is the law of conservation of energy?
The total energy in a system remains constant and cannot be created nor destroyed.
Formula for Energy efficiency?
Energy efficiency = (amount of usable final energy / amount of initial energy) * 100
Unit is percentage (%)
