Question
A massless beam is supported only at one point, called the pivot point, as shown in the diagram. A block with mass m1 sits at the left end of the beam, a distance L1 from the pivot point. A block with mass m2 sits at the right end of the beam, a distance L2 from the pivot point. L2 > L1. Calculate all torques about the pivot point, remembering that positive is anti-clockwise.
Select Yes, No, Less than, Equal to, or Cannot tell.
1) Given particular values of m1, m2, and L1, is it always possible to choose L2 (with L2 > L1) such that the masses have no angular acceleration?
2) Given particular values of L1 and L2, does the angular acceleration depend only on m1 / m2 ? (If it depends on the actual values of m1 and m2, put 'no'.)
3) If m1 * L1 = m2 * L2, is there a net (non-zero) torque?
4) If m1 = m2, will the masses have an angular acceleration?
Explanation / Answer
= m1L1 - m2L2
1) & 2) no angular acceleration means no torque onsystem
m1L1 - m2L2 = 0
m1L2 = m2L2
if L2 > L1 , then m1 = m2L2/ L1
3) no, torque will be zero.
4) yes , they have angular acceleration as L2 > L1