How far below the surface of the water is the boat's bottom when it is floating in water?

Question

A boat (with a flat bottom) and its cargo weigh 5,600 N. The area of the boat's bottom is 9 m². How far below the surface of the water is the boat's bottom when it is floating in water?

Answer 1

Well buoyant force = weight of water displaced = 5600 N

1 m³ of water has mass 1000 kg, so weight 1000 x 9.81 = 9810 N

So volume of water displaced = 5600 / 9810 m³

So required depth = volume / area of bottom = volume / 9 = (5600 / (9810 x 9)) m = 0.06 m = 6 cm