Assignment:
Question 1. A flat circular plate of copper has a radius of 0.265m and a mass of 42.4kg. What is the thickness of the plate? Answer in meters.
Question 2. The mass of the planet Saturn is 5.64*10^26 kg and its radius is 6*10^7m. Calculate density. Answer in units of kg/m^3.
Question 3. One cubic meter (1.0m^3) of aluminum has a mass of 2700kg, and a cubic meter of iron has a mass of 7860kg. Find the radius of a solid aluminum sphere that has the same mass as a solid iron sphere of radius 4.32cm. Answer in units of cm.
Question 4. This problem demonstrates dimensional analysis. A rope has a cross section A=9.1 m^2 and density p=2140kg/m^3. The “linear” density of the rope “mu” is defined to be the mass per unit length, in the form mu = p^xA^y. Based on dimensional analysis find the powers x and y.
a) x=-1, y=-1
b) x=1, y=2
c) x=-2, y=1
d) x=-1, y=1
e) x=-2, y=2
f) x=1, y=1
g) x=-2, y=-1
h) x=-1, y=2
i) x=1, y=-1
Question 5. A piece of pipe has an outer radius, an inner radius, and length as shown in the figure below.
The density is 7.9g/cm^3
What is the mass of this pipe? Answer in units of kg.
Question 6. How many seconds are their in a year? Answer in units of s/year.
Question 7. If 2 micrometerorite(s) (a sphere with a diameter of 1*10^-6 m) strikes each square meter of the moon each second, how many years would it take to cover the moon to a depth of 0.684m?
Hint: Consider a cubic box on the moon 1m on a side, and find how long it willl take to fill the box. Answer in units of years.
Question 8. Needing help, george asked, “If a chicken and a half can lay an egg and a half in a day and a half, how many days will it take one chicken to lay a dozen eggs? Assume 1 month has 30 days and select the best answer.
a) a dozen eggs in 24 days
b) a dozen eggs in 8 days
c) a dozen eggs in 2/3 of a month
d) a dozen eggs in 12 days
e) a dozen eggs in 18 days
f) a dozen eggs in 1/3 of a month
g) a dozen eggs in 6 days
h) a dozen eggs in 9 days
i) a dozen eggs in 16 days
Question 9. Assume the sun is mostly composed of hydrogen atoms. Assume the mass of the sun is 1.89*10^30kg, and the mass of a hydrogen atom is 1.672*10^-27kg. How many atoms are their in the sun? Answer in units of atoms.
Question 10. Assume that an oil slick consists of a single layer of molecules and that each molecule occupies a cube 1.09nm on a side. Find the area of an oil slick formed by 0.684m^3 of oil. Answer in units of m^2.
Question 11. Assuming that 68.6% of the earth’s surface is covered with water at an average depth of 1.01 mile(s), estimate the mass of the water on earth in kg.