Physics 2.4 - 2.7

Question 1

What is power

Answer 1

Power is the rate at which energy is transferred over time

Question 2

What is work done

Answer 2

Work done is the energy transferred to or from an object using a force over a certain distance

Question 3

What is the power formula in terms of energy

Answer 3

P = e/t

Question 4

What is the power formula in terms of work done

Answer 4

P = w/t

Question 5

What does the e and t stand for in the power formula and their units?

Answer 5

E stands for energy given in joules and the t stands for time given in seconds

Question 6

What does the w and t stand for in the power formula in terms of work done?

Answer 6

the w stands for work done given in joules and the t stands for time given in seconds

Question 7

When is it appropriate to use the power formula in terms of work done

Answer 7

When a force is involved to move an object

Question 8

When is it appropriate to use the regular power formula

Answer 8

When no force is involved

Question 9

What is efficiency

Answer 9

Efficiency is a measurement of how efficient a device is when it comes to transferring energy

Question 10

What is the efficiency formula and what are the units of each variable in it

Answer 10

Efficiency = Useful energy output / Total energy input where efficiency can be given as a decimal or percentage, useful energy output and total energy input are given as joules

Question 11

Can a device be 100% efficient?

Answer 11

No device can be 100% efficient there is always some form of energy loss

Question 12

What are sankey diagrams

Answer 12

Sankey diagrams are diagrams that are used to show the flow or transfer of energy in a process

Question 13

Are sankey diagrams drawn to scale/

Answer 13

Sankey diagrams are always drawn to scale

Question 14

How do you measure the energy at a specific point on the sankey diagram

Answer 14

You take the width of that point on the sankey diagram and convert the units using the scale provided