A uniform bar AB is balanced on a knife-edge which is 60cm from B by a mass of 22g which hangs at C 10cm from A. Calculate the mass of the bar.

A. 133.2g
B. 66.0g
C. 60.0g
D. 22.0g

Correct Answer: Option B

B. 66.0g

Explanation

clockwise movement = anticlockwise movement

w x 10 = 22 x 30

w = 22×30/10

w = 66.0g