Chapter 1: Q30 DQ (page 390)

Identical-size lead and aluminium cubes are suspended at different depths by two wires in a large vat of water (Fig. Q12.30). (a) Which cube experiences a greater buoyant force? (b) For which cube is the tension in the wire greater? (c) Which cube experiences a greater force on its lower face? (d) For which cube is the difference in pressure between the upper and lower faces greater

Short Answer

Expert verified

The buoyant force on each of the lead and aluminum blocks is the same since they each displace the same amount of water. Lead will show more surface tension.

Step by step solution

Understanding about buoyant force and surface tension

Buoyant force- The net upward force on every item in a fluid is known as buoyant force. Objects that have a buoyant force that is larger than their own weight will float to the surface. The item will sink if the buoyant force will be less than the weight of the fluid displaced.

Surface Tension- The propensity of liquid surfaces to contract to their smallest possible surface area while at rest is known as surface tension. When items having a greater density than water, such razor blades and insects, float on water's surface because of surface tension, they don't become immersed at all.

Solution

Because the buoyant force is based on displaced volume, not mass or density, the buoyant force is directly proportional to this volume. As each have the same amount of water to displace, their buoyant forces are equal.

Lead having more density than aluminum will experience more surface tension as higher the density greater will be the surface tension.