Why is a magnetic field a vector quantity? a. directional force b. directional speed c. specified location d. it produces long field lines e. it produced field lines that are close together

The answer is A, a directional force.

Explanation:

For something to be a vector, it must have a value and a direction. A magnetic field always have a direction since goes from negative to positive. The magnetic field lines goes from one pole to the other one and increase his intensity near them.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =