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geniusboy [140]
3 years ago
10

a tourist boat is used for sightseeing in a nearby river. The boat travels 2.4 miles downstream and in the same amount of time.

it travels 1.8 miles upstream, if the boat travels at an average speed of 21 miles per hour in the still water, find the current of the river. show me the work
Mathematics
1 answer:
Gemiola [76]3 years ago
8 0

Answer:

The current of the river has a speed of 3 miles per hour

Step-by-step explanation:

Let's call v the speed of the boat in calm waters.

We know that:

v = \frac{d}{t}

Where d is the distance in miles and t is the time

When the boat travels down we have to:

d=2.4\ miles

If s is the speed at which the boat travels downstream and c is the speed of the river then

s=(v+c)

And

t=\frac{d}{s}\\\\t=\frac{d}{v+c}\\\\t=\frac{2.4}{21+c}

When the boat travels upstream we have to:

d=1.8\ miles

s=(v-c)

t=\frac{d}{s}\\\\t=\frac{d}{v-c}\\\\t=\frac{1.8}{21-c}

We know that the time he navigate upstream is the same time he navigate downstream

Then:

\frac{2.4}{21+c}=\frac{1.8}{21-c}

We solve the equation for c

2.4*(21-c)=(21+c)*1.8

50.4-2.4c=37.8+1.8c

50.4-37.8=1.8c+2.4c

4.2c=12.6

c=\frac{12.6}{4.2}

c=3\ miles\ per\ hour

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artcher [175]

The steps to use to construct a frequency distribution table using sturge’s approximation is as below.

<h3>How to construct a frequency distribution table?</h3>

The steps to construct a frequency distribution table using Sturge's approximation are as follows;

Step 1: Find the range of the data: This is simply finding the difference between the largest and the smallest values.

Step 2; Take a decision on the approximate number of classes in which the given data are to be grouped. The formula for this is;

K = 1 + 3.322logN

where;

K= Number of classes

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Step 3; Determine the approximate class interval size: This is obtained by dividing the range of data by the number of classes and is denoted by h class interval size

Step 4; Locate the starting point: The lower class limit should take care of the smallest value in the raw data.

Step 5; Identify the remaining class boundaries: When you have gotten the lowest class boundary, then you can add the class interval size to the lower class boundary to get the upper class boundary.

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Read more about  frequency distribution table at; brainly.com/question/27820465

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6 0
2 years ago
25 POINTS Trina's Toy Company charges $0.85 per pound to ship toys.
d1i1m1o1n [39]

Answer:

Part A

C = $.85p

For 2 pounds , the charge is $1.70

Part B

C = $.05 * p

Step-by-step explanation:

Part A

Cost = charge per pound * pounds

We know the charge per pound is $.85

C = $.85 * p

We want to ship 2 pounds

C = .85*2

C = 1.70

Part B

Cost = charge per pound * pounds

We know the charge per pound is now $.05

C = $.05 * p


3 0
3 years ago
During the mayoral election,two debates were held between the canidates. The first debate lasted 1 4/5 hours. The second one las
Andrews [41]

Answer:

3\frac {6}{25} hrs \ or \ 3 hrs\  14 mins \ 24 sec

Step-by-step explanation:

The question calls requires one to get the product of the given time. Since first debate lasted for :

1\frac {4}{5} \ hrs

-and the second lasted

1\frac {4}{5} hrs times more than the first then the second took then the first step will involve converting the mixed fractions into improper fraction which will be:

\frac {9}{5}

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\frac {9}{5}\times\frac{9}{5}\\\\=\frac{81}{25}=3\frac{6}{25}hrs

5 0
3 years ago
A baseball player hits a pitched ball when it is 4 ft above the ground. The initial upward velocity is 80 ft/s. How
iren [92.7K]

Answer:

t=+4.06

Step-by-step explanation:

when the baseball hits the ground, the height will be 0.

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since time cannot be negative, only the positive value can be taken.

this is 4.06, to 3 significant figures.the time taken is 4.06 seconds.

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x - 8 = </= 13

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