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A 200g block on a 50cm long string swings in a circle, it's frictionless and 75rpm. What is its speed and tension on string

User Sstchur
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2 Answers

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angular velocity = (75x2pie)/60
=2.5pie ras^-1
linear velocity(or speed) at end of string, v = radius x angular velocity
v= 0.5 x 2.5pie
v=3.93 ms^-1

tension of string (I beleve is centeral force aplied by string), F= (mv^2)/r
F= (0.2 x 3.93^2)/0.5
F=6.18 N
(sorry if wrong)
User Alex Chesters
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3 votes

The speed of the block is given by:


image

Where,

w: angular speed

r: radius of the circular path.

The angular velocity must be in radians over seconds:


image

The radius must be in the subway:


image

Then, the speed is given by:


image


image

The tension of the rope is the centripetal force.

By definition, the centripetal force is:


image

Where,

m: mass of the block in kilograms

Substituting values:


image

Answer:

its speed and tension on string are:


image

User LinnTroll
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