Two soccer players kick a soccer ball back and forth along a straight line. The first player kicks the ball 16 m to the right to the second player. The second player kicks the ball to the left weakly; it only moves 3.1 m before stopping. (Consider the right to be the positive direction. Where applicable, indicate the direction with the sign of your answer. All distances are in meters.)

a

The total distance is

b

The displacement is

Explanation:

From the question we are told that

        Distance traveled by the ball for first player to the right

        Distance  traveled by the ball for second player to the left

The total distance traveled by the ball is mathematically represented as

Substituting values

The displacement is mathematically represented as

This is because displacement deal with direction and from the question we are told that right is positive and left is negative

          Substituting values  

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 =