Set 13 solutions

Q4.15

Height makes a difference. Width does not. If it were to hold mercury, it would have to be very, very strong, because mercury is so dense.

Q4.24

P4.19

P4.26

P4.27

C4.7

This would be great if it would work. No heavy tanks to mess with, no worries
about running out of air.

The problem is that pressure increases with depth much more rapidly in water
than in air, because of its higher density. Recall that

change in p = D g h.

So, we can follow either of two paths down to the diver.

Going down through the water to the outside of the diver's chest, we see
a big pressure increase, because water is dense.
Going down the hose to the diver's lungs, we see very little pressure increase,
becase air is much less dense.

Thus the water pressing inward on the diver's chest is at a much higher pressure
than the air inside pressing out. The diver cannot inhale.

Jacques Cousteau invented SCUBA gear to feed air to the diver equal in pressure
to that of the water, so that the diver can breath comfortably.

C4.9

The water level will remain the same.

Initially, the ice is floating, so it displaces its weight in water. After it melts, it is just water, which displaces its volume in water, which is the same as its weight in water, since it is just water.