Flying with the wind, a small plane flew 340 mi in 2 h. flying against the wind, the plane could fly only 310 mi in the same amount of time. find the rate of the plane in calm air and the rate of the wind.

Rate of the plane in calm air is 162.6 miles per hour and the rate of the wind is 7.5 miles per hour

Given that  

Flying with the wind, a small plane flew 340 mi in 2 hrs .

Flying against the wind, the plane could fly only 310 mi in 2hrs  

Need to find the rate of the plane in calm air and the rate of the wind.

As Flying with the wind, a small plane flew 340 mi in 2 hrs ,  

So speed(rate) of the plane when  Flying with the wind = miles per hour

As flying against the wind, the plane could fly only 310 mi in 2hrs ,

So speed (rate) of the plane when  Flying against the wind = miles per hour

Let assume speed(rate) of the pane in calm air = x miles per hour  

And speed(rate) of the wind = y miles

As  speed ( rate ) while Flying with the wind = speed(rate) of the pane in calm air + speed(rate) of the wind

=> 170 = x + y

=> x + y = 170   ------(1)

As  speed ( rate ) while Flying against the wind = speed(rate) of the pane in calm air - speed(rate) of the wind

=> 155 = x – y

=> x – y = 155  ------(2)

Adding (1) and (2) , we get

(x + y) + ( x - y)  = 170 + 155

=> 2x = 325

=>

Substituting value of x in equation 1 , we get

162.5 + y = 170

=> y = 170 – 162.5 = 7.5  

Hence rate of the plane in calm air = x = 162.6 miles per hour and the rate of the wind = y = 7.5 miles per hour.

46.2+112.3

step-by-step explanation:

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.