Answer:

Explanation:
d = Diameter of spot = 30 μm
r = Radius of spot = 
P = Power of the laser = 
A = Area = 
Intensity is given by

The light intensity within this spot is 
The statement that is a quantitative observation is that bird has four different colors on it (option B).
<h3>What is a quantitative research?</h3>
A quantitative research is a systematic scientific investigation of quantitative properties and phenomena and their relationships, using statistical methods.
A quantitative observation has to do with numbers or numeric analysis.
This suggests that the statement that is a quantitative observation is that bird has four different colors on it.
Learn more about quantitative observations at: brainly.com/question/1434538
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Answer:
Average velocity

Average speed,

Explanation:
(a)Average velocity
We have to find the average velocity. We know that velocity is defined as the rate of change of displacement with respect to time.
To find the average velocity we have to find the total displacement.
since displacement along east direction is 50m
and displacement along west=40m
so total displacement,

total time,

therefore, average velocity

(b)Average Speed:
Average speed is defined as the ratio of total distance to the total time
it means
Average speed= total distance/total time
here total distance,

and total time,

therefore,
Average speed,

Explanation:
We have,
Length of a metal rod is 55 cm or 0.55 m
Change in length is 0.2 cm or 0.002 m
It is required to find the change in temperature of a metal rod. The coefficient of linear expansion is given by :

is the change in temperature

So, the change in temperature is 303.03 degrees Celsius.
The anwser is C it can also be A but C would make the most sense