Name the SI unit for energy
What is a joule
This type of energy is made up of the total kinetic energy of the moving atoms and molecules of an object.
Thermal energy
What 2 conditions must be met for work to be done?
1. Object must move as a result of a force acting on it.
2. The acting force must be in the direction of the object's motion
What is the purpose of a machine ?
A machine makes work easier
Calculate the work with the following information :
F= 19.6 N
D=1.5m
w=29.4 J
In science, energy is defined as the
ability to move or change matter in some way
What is Chemical Energy?
Chemical energy is the energy stored in the chemical bonds of the molecules of a substance
How does gravity do work?
Gravity produces a downward force. Gravity does work as potential energy is converted to kinetic energy.
1. A machine can change the size of a force
2. a machine can change the direction of a force
3. A machine can change the distance over which a force is applied
What is the distance of work completed if the force is 19.6 N and the work done was 58.8 J?
D= 3m
d=w/f
What does the kinetic energy of any moving object depend on?
This type of energy can travel through space in the form of waves and is the energy reflected or emitted from objects.
Electromagnetic energy or light waves
What is the equation for work?
W=FxD
What is a machine's mechanical advantage?
The number of times a machine increases or decreases the input force.
What is the SI unit for power?
W= watt
What is the formula for Kinetic Energy?
KE=1/2 x m x v2
Name two types of potential energy
Gravitational and elastic
What is the mathematical equation for the following sentence?
Power is the work an object does divided by the time it takes to do the work.
P = w/t
What does the law of conservation of energy state?
Energy cannot be created nor destroyed, it can only be converted from one form to another or transferred from one object to another.
Solve for kinetic energy :
m=100kg
v=10m/s
ke=? in J
5,000 J
What is the equation for gravitational potential energy? Extra 50 points if you tell me what the value for g is.
PE=m x g x h
G= 9.8m/s2
The total __________ __________ of an object is the sum of its potential and kinetic energies
mechanical engergy
What is the definition of work?
What is the definition of power?
Power is the amount of work done each second.
How does the law of conservation of energy apply to machines. Does this help us to conserve our own energy when we use machines?
yes. The law of conservation of energy demonstrates energy being transferred from one from to another. Machines change the force strength or the distance over which the force is applied.
Solve for PE:
m= 62.0 kg
g= 9.8m/s2
h=5.0 m
PE=? in J?
3,038 J