quiz 4

Question 1

What is the equation for calculating kinetic energy(in words)

Answer 1

kinetic energy= 0.5 x mass x velocity squared

Question 2

what is the equation for calculating efficiency as a decimal?

Answer 2

efficiency= useful energy output/total energy input

Question 3

How can we reduce the amount of energy objects lose by heating?

Answer 3

increasing thermal insulation

Question 4

What is the relationship between thermal conductivity and the rate of energy transfer across the material?

Answer 4

The higher the thermal conductivity, the higher the rate of energy transfer across the material

Question 5

What is the equation for calculating efficiency as a percentage?

Answer 5

efficiency= 100 x useful energy output/total energy input

Question 6

what does dissipated mean?

Answer 6

Lost to the surroundings as thermal energy

Question 7

what are the units for mass

Answer 7

kilograms,kg

Question 8

what are units for velocity

Answer 8

meters per second ,m/s

Question 9

If a machine has moving parts, how can we reduce unwanted energy transfers?

Answer 9

Lubrication

Question 10

Why is efficiency never 100%

Answer 10

Energy is always dissipated to the surrondings

Question 11

What is the equation for calculating kinetic energy(in symbols)?

Answer 11

Ek=0.5 x m x v squared

Question 12

what is wasted energy?

Answer 12

Energy that is not transferred in useful ways