34. State the number of significant digits in each of the following measurements.
a. 0.000 03 m c. 80.001 m
b. 64.01 fm
d. 0.720 ug

Describe the path of a ray that approaches a mirror parallel to the principal axis.

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

The earth is constantly spinning on its axis, like you might spin a basketball on your finger. it is this spinning of the earth that causes