All sections Flashcards
What is motion?
It occurs when an imaginary line joining the object to the reference point changes in length, direction, or both.
What is uniform motion?
It describes an object that is travelling at a constant rate of motion in a straight line. This includes uniform acceleration.
What is average speed? What is the formula and what do the letters represent?
It is uniform motion that involves travelling a distance in a specified time.
Formula: v= Δd/Δt
v: average speed (m/s)
d: distance travelled (m)
t: time elapsed (s)
How is average speed represented in a graph?
time t (s): x axis
distance d (m): y axis
called a distance-time graph
slope: speed
Describe a speed-time graph
time t (s): x axis
speed v (m/s): y axis
- a horizontal line means uniform motion
- finding the area below the line gives you the distance travelled
What is velocity? What is the average velocity formula?
It describes both the rate of motion and the direction of an object.
Formula
->v = Δ->d/Δt
arrow on v: average velocity (m/s (direction))
arrow on d: displacement (m (direction))
t: time elapsed (s)
What is a scalar quantity? What is a vector quantity?
A scalar quantity indicates “how much” (the magnitude) of the quantity. A vector indicates the magnitude AND the direction of the quantity. An arrow gets added above a symbol to demonstrate that it is a vector quantity.
What is displacement?
It is like distance, but instead is a vector quantity (also shows direction) that the movement occurs in. It is a measurement of the distance AND the direction change in position of an object from a reference point.
Describe a position-time graph.
time t (s): x axis
position d(with arrow) (m): y axis
velocity: slope
Describe a velocity-time graph.
time t (s): x axis
velocity v (m/s) (direction): y axis
Area under line is displacement/position
slope: acceleration
What is acceleration? What is the formula?
A change in velocity during a specific time interval. It is a vector quantity.
Formula
acceleration = change in velocity/change in time or time interval
acceleration: m/s2
Describe how positive/increasing acceleration occurs.
1) when the change in both the magnitude of the velocity and the direction are positive
2) when the change in both the magnitude of the velocity and the direction are negative
Describe how negative/decreasing acceleration occurs.
1) when the change in the magnitude of the velocity is negative while the direction is positive
2) when the change in the magnitude of the velocity is positive while the direction is negative
What is force? What is it measured in? What is the formula for force?
A push or pull on an object. When an object is at rest, all forced acting on it are balanced. It is measured in newtons.
Formula:
F= ma
(mass times acceleration) (kg times m/s2)
Is energy required to maintain uniform motion?
No
When is work done on an object? What is the formula for work?
When a force moves an object that is in the direction of the force, then work is done. It is measured in joules.
Formula
W=Fd
J= N x m = kg x m/s2 x m = kg x m2/s2
What are the three conditions for work to be done on an object?
1) there must be movement
2) there must be a force
3) the force and the distance the object travels must be in the same direction
What is energy?
Energy is the ability to do work. Work and energy are basically the same thing
E = W
What is chemical energy?
It is the potential energy stored in the chemical bonds of compounds. e.g. wood burning
What is electrical energy?
Work done by moving charges.
What did the volta pile prove?
It constituted the first battery, resulting in it providing evidence of a connection between chemical energy and electrical energy.
Is magnetism a form of energy?
yes
What are two forms of energy that can be produced from electricity?
Light and heat energy
What is nuclear energy? Explain nuclear fission and fusion.
Nuclear energy is the potential energy stored in the nucleus of an atom. When the nucleus of an atom is split (nuclear fission) or when the nuclei of two atoms combine (nuclear fusion), this energy is released.
What is kinetic energy?
Something doing work because of its MOTION.
What is gravitational potential energy?
An object raised above Earth’s surface that has the potential to do work because of its position.
What is mechanical energy?
It is the sum of the energy of motion and position.
What is thermodynamics?
The study of the interrelationships of heat, work, and energy.
What is heat?
The transfer of thermal energy from a hot object to a cold object.
Can an object have both potential and kinetic energy, or just one?
It can have both.
What is potential energy? What is the formula?
Potential energy has the potential to do work. It is energy that is stored or held in readiness.
Ep(grav) = mgh
m: mass (kg)
g: acceleration due to gravity (9.81m/s2)
h: height (m)
What is the formula for weight?
Mass times gravity
What is elastic potential energy?
This type of energy is stored in a stretched or compressed spring, a trampoline, a diving board, etc. The force is often used to stretch an elastic.
What is chemical potential energy?
The energy found in chemicals, stored in the bonds of chemical compounds. When a chemical reaction takes place and work is done, this potential energy is released.