**Question**

**A man of mass 50 kg ascends 30 steps of a staircase in 15 seconds. If the height of each step of the staircase is 20 cm, find the power of the man (g = 9.8 m/s ^{2}). [Ans. 196 W] **

**Answer**

Mass (m) = 50 kg

Height (h) = 30 × 20 cm = 6 m

Time (t) = 15 s

**Step 1: Calculation of work**

Work (W) = mgh

= 50 × 9.8 × 6 = 2940 J

**Step 2: Calculation of Power**

Power (P) = Work\over Time

= 2940\over 15 = 196 W