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Vesna [10]
3 years ago
13

If the stone loses 10% of its speed in 10 s of grinding, what is the force with which the man presses the knife against the ston

e?
Physics
1 answer:
saul85 [17]3 years ago
7 0
W1=200rpm*2pi/60=20.9rad/s

w2=200rpm-.10(200rpm)=180rpm
 
180rpm*2pi/60=18.8rad/s

a=(18.8-20.9)/10= -.21rad/s^2

I=1/2(28)(.15)^2
 I=.315kg*m^2
Torque= -.21(.315)=.06615 N*m
Friction force= -.06615/.15=-.441 N
Normal force of man=.441/.2= 2.205 N
 Final answer: -2.205 N


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Generally, the equation for is mathematically given as

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