(Solved): PHYS 112 - Assignment 1 (Introductory/Preliminary Material) N.B. You must show your work and all num ...

PHYS 112 - Assignment 1 (Introductory/Preliminary Material) N.B. You must show your work and all numerical answers must be given with units and to the correct number of significant figures. Physical Quantities and Units Earth orbits the Sun at an average distance of 149.60 million km . One complete orbit takes 365.256 days (1 sidereal year), during which time Earth has traveled 940 million km. Calculate the Earth's speed in its orbit around the Sun in

, and

. (a) Starting with the definition

, find the number of kilometers in 1.00 mile. (b) In medicine, volumes are often expressed in milliliters ( ml or mL ). Show that a milliliter is the same as a cubic centimeter. (c) How many cubic centimeters of water are there in a 1.00 L bottle of drinking water? Precision and Significant Figures 3. Express each of the following approximations of

to six significant figures: (a)

and (b)

. (c) Are these approximations accurate to that precision? 4. Cell walls. Although these quantities vary from one type of cell to another, a cell can be

in diameter with a cell wall 50.0 nm thick. If the density (mass divided by volume) of the wall material is the same as that of pure water, what is the mass (in mg) of the cell wall, assuming the cell to be spherical and the wall to be a very thin spherical shell? Scaling and Estimation 5. Space station. You are designing a space station and want to get some idea how large it should be to provide adequate air for the astronauts. Normally, the air is replenished, but for security, you decide that there should be enough to last for two weeks in case of a malfunction. (a) Estimate how many cubic meters of air an average person breathes in two weeks. A typical human breathes about

per breath. (b) If the space station is to be spherical, what should be its diameter to contain all the air you calculated in part (a)? Vectors 6. A plane leaves Seattle, flies 85 mi at

north of east, and then changes direction to

south of east. After flying 115 mi in this new direction, the pilot must make an emergency landing on a field. The Seattle airport facility dispatches a rescue crew. (a) Sketch a diagram showing the plane's displacement; label your diagram. (b) In what direction and how far should the crew fly to go directly to the field? Use components to solve this problem. 7. Muscle Attachment. When muscles attach to bones, they usually do so by a series of tendons, as shown in Figure 1. In the figure, five tendons attach to the bone. The uppermost tendon pulls at

from the axis of the bone, and each tendon is directed

from the one next to it. (a) If each tendon exerts a 2.75 N pull on the bone, use vector components to find the magnitude and direction of the resultant force on this bone due to all five tendons. Let the axis of the bone be the

axis. (b) Draw a graphical sum to check your results from part (a). 1 PHYS 112 - Assignment 1 (Introductory/Preliminary Material)