Efficiency F

What kind of energy does an object possess when it's resting on top of the hill?

• Potential Energy

• Chemical Energy

• Kinetic Energy

• All of the above

Tags

NGSS.MS-PS3-2

Total energy = 200J
Useful energy = 20J

Workout the efficiency of this lightbulb.
 $efficiency\ =\ \frac{useful\ enegy}{total\ energy\ in}\ \times100$  

• 100%

• 80%

• 40%

• 10%

Tags

NGSS.MS-PS3-4

A lightbulb with efficiency of 10% would be

• efficient

• inefficient

Total energy = 350J
Useful energy = 70J

Workout the efficiency of this iphoneX.
 $efficiency\ =\ \frac{useful\ energy}{total\ energy\ in}\ \times100\%$  

• 100%

• 80%

• 40%

• 20%

Balmain's car needs 8600J of energy to power it. If 5000J is changed into useful energy, how much energy is wasted?

• 13600J

• 3600J

• 5000J

• 8600J

Total energy = 250J
Useful energy = 50J

Workout the efficiency of these fairy lights. $efficiency\ =\ \frac{useful\ energy\ output}{total\ energy\ input}$  

• 0.13

• 0.14

• 0.2

• 0.25

What do most machines waste energy as?

• heat

• chemical energy

• light

• sound waves

What is the maximum possible efficiency of a machine?

• 101%

• 50%

• 100%

• 0%

Total energy = 800J
Useful energy = 600J

Workout the efficiency of this iphoneX.
 $efficiency\ =\ \frac{useful\ energy}{total\ energy\ in}\ \times100\%$  

• 95%

• 75%

• 65%

• 20%

Total energy = 250J
Useful energy = 220J

Workout the efficiency of this iphoneX.
 $efficiency\ =\ \frac{useful\ energy}{total\ energy\ in}\ \times100\%$  

• 99%

• 88%

• 66%

• 22%