A dentist\'s drill accelerates from rest at 640 r a d / s 2 for 2.00 s and then

Question

A dentist's drill accelerates from rest at 640rad/s2for 2.00s and then runs at constant angular velocity for 6.65s . Through how many total revolutions has the drill turned?

In the figure, the meterstick's mass is 0.165kg and the string tension is 2.60N .

Find the unknown mass m.      Find the upward force the fulcrum exerts on the stick.  

A dentist's drill accelerates from rest at 640rad/s2for 2.00s and then runs at constant angular velocity for 6.65s . Through how many total revolutions has the drill turned? In the figure, the meterstick's mass is 0.165kg and the string tension is 2.60N . Find the unknown mass m. Find the upward force the fulcrum exerts on the stick.

Explanation / Answer

theta=1/2*640*2^2

=1280 radians

w after 2 second

w=w0+alpha*t

=640*2

=1280 rad/s

so theat1=1280*6.65

=8512 radians

So total angular displacement=8512+1280

=9792 radian

=1558.44 revolutions

b.)from above figure now from moment balance we have

0.165*9.81*0.3=2.6*x

x=0.187 m ans

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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