WAEC Physics 2015 Objective — Question 13
Question 13 of 50 from the West African Examinations Council (WAEC) Physics 2015 Objective paper, with the correct answer and a full explanation.
Advertisement
A uniform bar AB is balanced on a knife-edge which is 60 cm from B by a mass of 22 g which hangs at C, 10 cm from B. Calculate the mass of the bar.
- A. 133.2 g
- B. 66.0 gCorrect
- C. 60.0 g
- D. 22.0 g
Explanation
Taking moments about the pivot: M × (50−40) = 22 × (40−10) → M×10 = 22×30 → M = 66 g.
Advertisement
Sign up free to unlock
- Score tracking
- Practice history
- Saved questions
- Progress dashboard
- Personalized sessions
- Weak-topic breakdown
…and/or go further with premium services and No Ads.