Work and Energy
Terms 20
1
Work
Force applied through a displacement. Requires both application of force and displacement of an object by that force.
2
Work formula 
W = F × d, where W is work in Joules, F is force in Newtons, and d is displacement in meters.
3
Work at an angle
When force is applied at an angle θ to displacement, work is calculated as W = F cos(θ) × d.
4
Work scalar quantity
Work is a scalar quantity, meaning it has magnitude but no direction.
5
Power
The rate at which work is done. Calculated as P = W/t, where W is work and t is time.
6
Power units
Power is measured in Watts (Joules per second). 1 horsepower equals 746 Watts or 0.746 kW.
7
Energy
The ability to produce a change in the environment or to do work. Measured in Joules.
8
Mechanical energy
Energy due to position or movement, encompassing kinetic and potential energy.
9
Kinetic energy
Energy possessed by an object because it is in motion. Depends on mass and velocity of the object.
10
Kinetic energy formula
KE = ½mv², where m is mass in kilograms and v is velocity in meters per second.
11
Work-Energy Theorem
Work done on a system equals the change in the system's energy. W = ΔE.
12
Gravitational Potential Energy
Stored energy of an object due to its gravitational interaction. Equals the product of weight and height above a reference level.
13
Gravitational Potential Energy formula
GPE = mgh, where m is mass, g is gravitational acceleration, and h is height above reference level.
14
Arbitrary Zero Point
You must select a reference point for zero potential energy in gravitational potential energy calculations.
15
Path independence of GPE
Gravitational potential energy depends only on vertical height change, not on the path taken.
16
Elastic Potential Energy
Energy stored by stretching, compressing, or bending an object such as springs or bows.
17
Mechanical energy
Sum of kinetic and potential energy in a system. ME = KE + PE.
18
Conservation of Mechanical Energy
In systems with no energy losses, total initial energy equals total final energy. (KE + PE)initial = (KE + PE)final.
19
Conservative forces
Forces where work done is independent of the path taken. Examples include gravity, elastic, and electric forces.
20
Non-conservative forces
Forces where work done depends on the path taken. Examples include friction and air resistance.