So i am having alot of problems in scientific notation. with these questions

Question

The diameter of the average cell in the human body is 1x10^-5 meters. The diameter of a grain of sand is about 2x10^-4 meters. The diameter of a human hair is about 0.000025.

 

Part A: what is the diameter of a human hair written in scientific notation?

 

Part B: How many times longer is the diameter of a grain of sand than the diameter  of the average cell in the human body? show your work

 

Part C: Given that one meter =1x10^9 nanometers what is the diameter of the average cell in the human body? show your work.

 

Part D: The smallest know bacteria  are from the genus mycoplasma and can measure as small as 300 nanometers in diameter. Given that 1 meter = 1x10^9 nanometers what is the diameter of the smallest bacteria in meters? Give your answer in scientific notation and show your work.

Answer 1

A)  0.000025 meters? = 2.5x10^-5 meters (you have to move the decimal 5 places to the left)

B)  2x10^-4 m for sand compared to 1x10^-5 meters for cell.  2x10^-4/1x10^-5 = 2x10¹ = 20 times 

C)  1x10^-5 meters x 1x10⁹ nanometers/meter = 1x10⁴ meters (10,000 meters)

D)  300 nanometers x 1 meter/1x10⁹ nanometers = 300x10^-9 meters = 3.00x10^-7 meters