50 men took a dip in a water tank 40 m long and 20 m broad. If the average displacement of water by a man is 4 m3, then the rise in the water level in the tank will be:
25 cm
Total volume of water displaced =(4×50)m3=200m3
∴Rise in water level =(20040×20) m
= 0.25 m = 25 cm