What is the mass of the man, it the length of a boat is 4m, width is 1.5m floating on a river sinks by 0.015 m when the man gets on the boat?

What is the mass of the man, if the length of a boat is 4m, width is 1.5m floating on a river sinks by 0.015 m when the man gets on the boat?

Solution:
Given that,
length = 4 m
width = 1.5 m
sink depth = 0.015 m
Additional volume displaced = length × width × sink depth = 4 × 1.5 × 0.015
= 4 × 0.0225
= 0.09 m³

We know,
Density of water = 1000 kg/m³

∴ Mass of displaced water = 0.09 × 1000
= 90 kg
By Archimedes' principle, mass of man = mass of displaced water = 90 kg