Conservation of energy and power Flashcards

1
Q

What is the conservation of energy?

A
  • Energy is transferred, stored or dissipated

- Not created or destroyed

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2
Q

What is dissipated energy known as?

A
  • Wasted energy
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3
Q

Describe energy transfers for a closed system.

A
  • Cold spoon dropped into hot soup
  • Soup flask is thermal insulator –> spoon + soup = closed system
  • Energy transferred from thermal store of soup to spoon (soup cools down a little)
  • Energy transferred but no energy has left (net change: zero)
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4
Q

Formulae for power:

A

P = E/t
P = W/t
- Energy transferred = Work done

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5
Q

What is a powerful machine?

A
  • Exerts strong force over a short time
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