Work Energy And Power

Question 1

Principle of conservation of energy

Answer 1

Energy cannot be created nor destroyed, can only change from one form to another

Meaning total amount of energy in a closed system remains constant, although how much of each form varies

Question 2

What are:
KE
GPE
Elastic
Chemical 
Nuclear
Internal

Answer 2

KE: energy of moving object
GPE: E gained by object when lifted or lost when dropped, ie due to height or position
Elastic: E of a stretched spring ie strain energy
Chemical: E contained in chemical substance
Nuclear: E in nucleus of an atom
Internal: E due to temp or state ie thermal/heat E

Question 3

2 types of energy

Answer 3

Transfers (ke, thermal, Sound, electrical, light) and stores (gpe, elastic, chemical, nuclear)

Question 4

Energy dissipation:

Answer 4

When transferred from form to form some is wasted or lost to surroundings.
Eg thermal sound or light
Significance of wasted energy depends on system

Question 5

Work done when

Answer 5

Object is moved over a distance by an external force applied in direction of it’s displacement
W=Fd

Question 6

More thoughts on work:

Answer 6

• energy is transfered from object to object
• it is amount of energy transferred hence
• unit is J
• if force acts in direction that object is moving object gains energy, if opp it loses