# physics

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A worker stands still on a roof sloped at an angle of 23° above the horizontal. He is prevented from slipping by a static frictional force of 540 N. Find the mass of the worker.

• physics -

m g sin 23 is the component of the worker's weight down the roof slope.

That equals the friction force 540 N

Solve M g sin23 = 540
to get the mass, M.

He's a pretty heavy guy, it seems.

• physics -

210.99

• physics -

497

• physics -

M*9.8*sin23=540
M*9.8=540/sin23 =1382.02
M=1382.02/9.8 =141.02kg

M=141.02kg

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