Write definitions for vector quantity, scalar quantity and resultant vector
Classify the following quantities as vectors or scalars: mass,
weight, temperature.
Force F = 5 N acts to the right.
Draw a fully labelled scale drawing of the 5 N force using a scale of
10 mm : 1 N. (Hint: Refer to Figure 5 on page 213.)
Draw and label the following vectors to scale (one below the other):
4.2.1 2F (Remember F = 5 N to the right)
4.2.2 0,5F
4.2.3 -F
4.2.4 -2F
Two vectors, F, and F, act on an object. F,= 2 N upwards and F, = 2 N
downwards.
Make a tail-to-head sketch vector diagram of the forces.
Explain whether F, and F, are equal vectors or not.
Calculate the resultant force.
CH​

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.

this would be about 43%

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 =