a grindstone used to sharpen tools is rotating at an angular velocity of 8 rad/s

Question

a grindstone used to sharpen tools is rotating at an angular velocity of 8 rad/s when an axe is pressed against it. Because of the torque produced on the grindstone by the force of friction between it and the axe, it comes to rest in four rotations.

a) Find the frictional force produced, assuming the grindstone is a cylinder of mass 5 kg and radius 0.4m.

b) If the coefficient of friction between the axe and grindstone is 0.4, find the normal force with which the axe was pressed against the grindstone.

Please, i need help, can someones show me how to do this in a really detail way. Thanks

Explanation / Answer

wf^2 -wi^2 =2*angular acceleration*theta => 8^2 -0 =2*angular acceleration*4*2*3.14 => angular acceleration = 1.274 rad/s2 a). torque =I* angular acceleration => f*0.4 =5*0.4^2/2 *1.274 => f= 1.274 N b). friction =coefficient of friction *N => N =1.274/0.4 =3.185 N

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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