Question

A top loading washing machine has a drum with a diameter of 52 cm and it spins at 1800 rpm.

A. What is the acceleration on the wall of the drum?

B. Draw the free body diagram for a drop of water at the wall as it is spinning?

C. If the drop of water has a mass of 1.5 g what is the force (apparent weight) of the drum on the drop?

D. If the washer is set on gentle so that it rotates at 1000 rpm what is the force on a 1.5 g drop of water?

Answer 1

a) a = v² / r

where v = rw

so,

a = r²w² / r

a = rw²

w = 1800 rpm = 1800 * (2/60) = 188.5 rad/sec

so,

a = 0.26 * 188.5²

a = 9238.38 rad/sec²

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Here is the free body diagram.

notice that i have not included friction

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c) N = mv² / r

N = mrw²

N = 13.856 Newtons

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d) w = 1000 rpm = 104.72 rad/sec

so,

N = 4.2768 Newtons