Why don't rocks stop falling in water?
Q2) Why does a rock not stop falling when dropped in water?
a) The rock keeps weighing more as it falls
b) The rock's density is always greater than the water it displaces
c) The water pushes harder from the top than the bottom of the rock.
d) The rock becomes slightly smaller and therefore denser as it feels more water
Pressure.
e) The water becomes less dense at greater depths
Q3) Would the rock stop falling if the liquid were compressible and reached a density greater than that of the rock?
a) Yes b) No
Mechanical Advantage Question
Q1) You are in a test of strength with a friend who has not taken physics. The idea is that both of you pump on a liquid, but are pumping against each other. Your friend says you can choose a lever pump of any design but
tells you that she or he is using a pump with a circular cross section piston with an area of ten square inches. If you want to have a 2x mechanical advantage over him, approximately what area of a piston will you choose?
a) 2 square inches b) 5 square inches c) 10 square inches d) 15 square inches e) 20 square inches
Q2) If you push your friend back by one foot, how much will you have had to move forward?
a) 6 inches
b) 12 inches
c) 18 inches
d) 24 inches
e) none of these
