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8 Energy – forces doing work

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Question 31

A heavy-duty industrial crane hoist has an efficiency denoted by $η\eta$ . During operation, the electric motor receives a total power input, $PinP_{\text{in}}$ , and does useful work lifting loads at a rate of $PusefulP_{\text{useful}}$ .

Write down an equation that expresses $\eta\,$ in terms of $PinP_{\text{in}}$ and $PusefulP_{\text{useful}}$ .

[1]

Markscheme

8 Energy – forces doing work Questions

GCSE
Physics
8 Energy – forces doing work

8 Energy – forces doing work

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8 Energy – forces doing work

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Question 31

Write down an equation that expresses $\eta\,$ in terms of $PinP_{\text{in}}$ and $PusefulP_{\text{useful}}$ .

[1]

Markscheme

8 Energy – forces doing work Questions

GCSE
Physics
8 Energy – forces doing work