Reducing Energy Waste Methods

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Which formula represents the calculation for power?

Power = mass × specific heat capacity × temperature change

Power = energy transferred + work done

Power = energy transferred ÷ time (correct)

Power = mass × specific heat capacity

In the context of energy transfers, what happens to energy?

Energy can be created or destroyed.

Energy can be transferred usefully, stored, or dissipated but not created or destroyed. (correct)

Energy can only be stored.

Energy cannot be stored.

What unit is power measured in?

Joules per kilogram per degree Celsius

Seconds

Joules

Watts (correct)

Why is energy often described as being 'wasted'?

Because in all system changes energy is dissipated, stored in less useful ways. Signup and view all the answers

What does a higher power rating imply in a motor?

The motor can do the same work faster. Signup and view all the answers

How would better thermal insulation contribute to energy efficiency?

By reducing the need for energy transfer. Signup and view all the answers

What is the formula to calculate efficiency of a system?

Efficiency = useful power output / total power input Signup and view all the answers

Which of the following materials would allow heat to travel through it more easily?

Plastic with high thermal conductivity Signup and view all the answers

How can the efficiency of a machine be increased according to the text?

By reducing waste output like proper lubrication Signup and view all the answers

Which energy source is classified as non-renewable?

Coal Signup and view all the answers

What effect does double glazing have in terms of energy transfer according to the text?

Decreases useful thermal energy loss Signup and view all the answers

How does reducing friction by proper lubrication impact energy loss in a motor?

Decreases energy lost as heat Signup and view all the answers

What is the formula to calculate kinetic energy?

$Ek = \frac{1}{2}mv^2$ Signup and view all the answers

When a moving ball hits a wall, which type of energy transfer occurs?

Kinetic to sound energy Signup and view all the answers

What is the formula for elastic potential energy stored in a spring?

$Ee = ke^2$ Signup and view all the answers

What does the specific heat capacity measure?

Energy required to raise temperature per unit mass Signup and view all the answers

What happens to kinetic energy when a vehicle slows down due to friction?

It transforms into thermal energy Signup and view all the answers

In the context of energy transfers, what is one way to reduce energy waste?

Increasing system efficiency Signup and view all the answers