Classify the statement below as either Speed or Velocity? A jeep was driving 40 mph
heading to the grocery store.

Hello There!

It is Speed.

Because in the question it is said that at which speed car is travelling.

Speed is a scalar quantity.

If it is velocity then first know this that it is a vector quantity.

It must include both magnitude and direction.

If it is velocity then it would be 40 mph east or west or north or south.

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 =