A firm wants to determine the amount of frictional torque intheir current line o

Question

A firm wants to determine the amount of frictional torque intheir current line of grindstones, so they can redesign them to bemore energy efficient. To do this, they ask you to test thebest-selling model, which is basically a diskshaped grindstone ofmass 1.2 kg and radius 9.10 cm which operates at 750 rev/min. When the power is shut off, you timethe grindstone and find it takes 27.0s for it to stop rotating. (a) What is the angular acceleration of the grindstone?(Assume constant angular acceleration.) (b) What is the frictional torque exerted on thegrindstone?
A firm wants to determine the amount of frictional torque intheir current line of grindstones, so they can redesign them to bemore energy efficient. To do this, they ask you to test thebest-selling model, which is basically a diskshaped grindstone ofmass 1.2 kg and radius 9.10 cm which operates at 750 rev/min. When the power is shut off, you timethe grindstone and find it takes 27.0s for it to stop rotating. (a) What is the angular acceleration of the grindstone?(Assume constant angular acceleration.) (b) What is the frictional torque exerted on thegrindstone?

Explanation / Answer

Given that the mass of grind stone is m = 1.2 kg radius of grind stone is r = 0.0910 m Initial angular velocity is 1 = 750 rev/ min = 78.5rad/s final angular velocity is 2 = 0 Time taken is t = 27.0s ---------------------------------------------------------------- The angular acceleration is = ( 2 - 1 )/t       = - 1 / t       = 2.90 rad/s2 torque is = I = (mr2 /2 ) = 0.0144 N.m

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.