When does the skater have the highest amount of kinetic energy? potential energy?

The mass in grams of a red blood cell is about 7.85 ×  10⁻¹¹ grams

Explanation:

To find the mass in grams of a red blood cell,

From,

Then,

From the question,

Density of a red blood cell is similar to that of water

Density of water = 1 g/mL = 1 g/ cm³

Then, Density of a red blood cell = 1 g/cm³

Now, we will find the volume a red blood cell.

From the question,  

Since the shape is like that of a thick disc, we can determine the volume by using the formula for volume of a cylinder.

Hence,

Volume of a red blood cell =

Where Is a constant (Take = 3.14)

is the radius

and is the thickness

Diameter of a red blood cell = 10 micrometers

Then, radius of a red blood cell = 10/2 micrometers = 5 micrometers

= 5 micrometers = 5 × 10⁻⁶ meters

and = 1 micrometer = 1 × 10⁻⁶ meters

Hence,

Volume of a red blood cell = 3.14 × (5 × 10⁻⁶)² × 1 × 10⁻⁶

∴ Volume of a red blood cell = 7.85 × 10⁻¹⁷ cubic meter (m³)

Convert this to cubic centimeter

(NOTE: 1 cubic meter = 1000000 cubic centimeter)

Hence,

Volume of a red blood cell = 7.85 ×  10⁻¹¹ cubic centimeter (cm³)

Now, for the mass

Density of a red blood cell = 1 g/cm³

Volume of a red blood cell = 7.85 ×  10⁻¹¹ cubic centimeter (cm³)

Then,

Mass = 1 g/cm³ ×  7.85 ×  10⁻¹¹ cm³

Mass = 7.85 ×  10⁻¹¹ g

Hence, the mass in grams of a red blood cell is about 7.85 ×  10⁻¹¹ grams