WAEC - Physics (2016 - No. 10)
A uniform metre rule is balanced on a fulcrum placed at the 35cm mark by suspending a mass of 120g at the 10cm mark. Calculate the mass of the metre rule.
60g
80g
120g
200g
Giải thích
Clock-wise moment = Anti-clock wise
Hence 120 × (35−10)= Xg ×(50−35)
120 × 25 = Xg × 15
Xg = 200g