posted by Roger .
1. A typical virus is a packet of protein and DNA or RNA and can be spherical in shape. The influenza A virus is a spherical virus that has a diameter of 85nm. If the volume of saliva coughed on to you by a friend with the flu is .010cm^3 and 10^-9 of that volume consists of viral particles, how many influenza viruses have just landed on you?
2. Keplar's Law of planetary motion says that the square of the period of a planet(T^2) is proportional to the cube of the distance of the planet from the sun (r^3). Mars is about twice as far from the sun as venus. How does the period of mars compare with the period of venus?