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Simple Torque Question

  • Thread starter putongren
  • Start date
  • #1
104
0
There is no answer in the back of the textbook to the problem I did. I'm self-studying, so can someone check if my answer is correct.


Homework Statement


The forearm accelerates a 3.6 kg ball at 7.0 m/s2 by means of the triceps muscle. The forearm is 30 cm long and is perpendicular triceps muscle. Calculate the torque and the force exerted by triceps muscles.





Homework Equations




[tex]\tau[/tex] = I[tex]\alpha[/tex]

[tex]\tau[/tex] = R x F

The Attempt at a Solution



a = 7.0 (m/s2), m = 3.6 (kg), r = .03 (m)
[tex]\tau[/tex] = I[tex]\alpha[/tex] , [tex]\alpha[/tex] = a/r, I = m*r2
= m*r2[tex]\alpha[/tex]
= m*r*a
= 3.6*.03*7
[tex]\tau[/tex] = .756

[tex]\tau[/tex] = r * F
F = [tex]\tau[/tex]/r
F = .756/.03
F = 25.2

Homework Statement





Homework Equations





The Attempt at a Solution

 

Answers and Replies

  • #2
rock.freak667
Homework Helper
6,230
31
Your answers are correct. Though you could have found the force (ma) first and then the torque (rF)
 

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