Energy Systems & Energy Formulas

Question 1

What is a system

Answer 1

• an object or group of objects we are interested in
• usually energy transfers will be involved

Question 2

What are the two types of systems, what are the differences

Answer 2

Open and closed

In open systems, energy can be transferred in and/or out, and the total energy changes.

In closed systems, no never us transferred in or out and the total energy remains constant.

Question 3

How do systems lose energy to their surroundings

Answer 3

Friction
Heat transfer
Dissipation (e.g radiation)

Question 4

How can energy loss be prevented

Answer 4

Insulation
Lubrication

Question 5

What’s the formula, units, and simplified formula for kinetic energy

Answer 5

KE=1/2 x mass x velocity^2
J, Kg, m/s^2
Ek = 1/2mv^2

Question 6

Give the formula, units and simplified formula for gravitational potential energy

Answer 6

GPE = mass x gravitational field strength x height
J, Kg, 9.8 m/s or 9.8N/Kg, m
Ep= mgh

Question 7

Give the formula, units, and simplified formula for elastic potential energy

Answer 7

Ee = 1/2 x spring constant x extension^2
J, N/m, m^2
Ee = 1/2ke^2

Question 8

The energy in the kinetic energy store of a moving object depends on its…

Answer 8

Mass and speed

Question 9

Elastic potential energy is the energy stored in an elastic object when…

Answer 9

Work is done on the object