# Isaac Physics 3.10

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#1
I need some help with this question:
My washing machine has a spin speed of 1200, r, p, m,1200rpm, and a drum radius of 20, c, m,20cm. Calculate how fast clothes go when up against the side of the drum when the machine is spinning. Give your answer to 2 significant figures.
Thanks.
0
10 months ago
#2
So use the equation, speed = distance / time
Distance is how far a point in the washing machine has moved so it will be the circumference multiplied by the number of revolutions
Divide this by how long it takes to travel this distance. So the time for 1200 revolutions to occur
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#3
Will it not be angular velocity?

(Original post by Dominininc)
So use the equation, speed = distance / time
Distance is how far a point in the washing machine has moved so it will be the circumference multiplied by the number of revolutions
Divide this by how long it takes to travel this distance. So the time for 1200 revolutions to occur
0
10 months ago
#4
You've got radius and angular velocity, The tangential speed at that radius (given that it's rigidly rotating about the centre of rotation) is given by the product of the two. Obviously you're making the assumption that the clothes aren't slipping while against the side (otherwise you'd be unable to solve this.)
1
#5
(Original post by Callicious)
You've got radius and angular velocity, The tangential speed at that radius (given that it's rigidly rotating about the centre of rotation) is given by the product of the two. Obviously you're making the assumption that the clothes aren't slipping while against the side (otherwise you'd be unable to solve this.)
Cheers m8
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10 months ago
#6
(Original post by ryanrobsonTV)
Will it not be angular velocity?
No that will give you the speed of the clothes. distance/time

You get the same answer as going from the angular velocity direction as those equations are derived from this.
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