Post-UTME Physics 2005 Objective — Question 22
Question 22 of 23 from the Post-UTME Screening (Post-UTME) Physics 2005 Objective paper, with the correct answer and a full explanation.
Advertisement
A block and tackle system is used to lift a load of 20N through a vertical height of 10.5m. If the efficiency of the system is 40%, how much work is done against friction
- A. 310.0JCorrect
- B. 300.0J
- C. 290.0J
- D. 200.0J
Explanation
Work output = 20 x 10.5 = 210J. Since efficiency = output/input, input = 210/0.4 = 525J. Work against friction = input - output = 525-210 = 315J (closest listed option A).
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.