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3 years ago

15

A boat has a speed of 5 mph in calm water. It takes the boat 3 hours to travel updtream but only 2 hours to travel the same dist

ance downstream. Using the data in the table, what is the value of c, the speed current?

1 answer:

N76 [4]3 years ago

8 0

<span>
2(5+c)=3(5-c)
solve for c
10+2c=15-3c
5c=5
c=1</span>

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The value of X is ...

Alex787 [66]

Step-by-step explanation:

sums of external angles of triangle =360°

360 - 130 -134

x = 96°

8 0

3 years ago

An alloy is a mixture of metals. Suppose that a certain alloy is made by mixing 50 g of an alloy containing 12% copper with 78 g

givi [52]

Given :

An alloy is a mixture of metals. Suppose that a certain alloy is made by mixing 50 g of an alloy containing 12% copper with 78 g of an alloy containing 92% copper.

To Find :

How many grams of copper are in the resulting mixture what percentage of the resulting mixture is copper.

Solution :

Mass of copper in 50 gm alloy = $50\times 0.12 = 6\ gram$ .

Mass of copper in 78 gm alloy = $78\times 0.98 = 76.44\ gram$ .

Total mass of copper, ( 6 + 76.44 ) gm = 82.44 gram.

Percentage of copper in resulting mixture :

$\%=\dfrac{82.44}{50+78}\\\\\%=64.4\ \%$

Hence, this is the required solution.

8 0

4 years ago

Math help! Is this correct? If not what’s the real answer

miv72 [106K]

Answer:

It's correct

Step-by-step explanation:

Good job! arcsin(0.9659) is indeed 75 degrees

3 0

3 years ago

the empire state building is 1250 feet tall. IF an object is thrown upward from the top of the building at an initial velocity o

ss7ja [257]

Answer:

Time for the object to get h(max) s = 1.1875 sec

h (max) = 1272.57 feet

Down time for the object to hit the ground = 4.25 sec

Step-by-step explanation:

The relation

h(s) = - 16*s² + 38* s + 1250 (1)

Is equivalent to the equation for vertical shot

Δh = V(i)*t - 1/2g*t² (in this case we don´t have independent term since the shot is from ground level. We can see in (1), the independent term is 1250 feet ( the height of the empire state building), the starting point of the movement.

The description of the movement is:

V(s) = V(i) - g*s ⇒ V(s) = 38 - 32*s

At h(max) V(s) = 0 38/32 = s

So the maximum height is at s = t = 1.1875 sec

The time for the object to pass for starting point is the same

t = 1.1875 sec

h(max) is

h(max) = - 16* (1.1875)² + 38 (1.1875) + 1250

h(max) = - 22,56 + 45.13 + 1250

h(max) = 1272.57 feet

Time for the object to hit the ground is

h(s) = - 1250 feet

-1250 = - 16 s² + 38*s + 1250

-16s² + 38s = 0

s ( -16s + 38 ) = 0

First solution for that second degree equation is x = 0 which we dismiss

then

( -16s + 38 ) = 0 ⇒ 16s = 38 s = 38/16

s = 2.375 sec and we have to add time between h (max) and to get to starting point ( 1. 1875 sec)

total time is = 2.375 + 1.875

Total time = 4.25 sec

4 0

3 years ago

1.How many combinations are possible from the letters HOLIDAY if the letters are taken?

Lesechka [4]

Using the combination formula, it is found that:

1. A. 7 combinations are possible.

B. 21 combinations are possible.

C. 1 combination is possible.

2. There are 245 ways to group them.

<h3>What is the combination formula?</h3>

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by:

$C_{n,x} = \frac{n!}{x!(n-x)!}$

Exercise 1, item a:

One letter from a set of 7, hence:

$C_{7,1} = \frac{7!}{1!6!} = 7$

7 combinations are possible.

Item b:

Two letters from a set of 7, hence:

$C_{7,2} = \frac{7!}{2!5!} = 21$

21 combinations are possible.

Item c:

7 letters from a set of 7, hence:

$C_{7,7} = \frac{7!}{0!7!} = 1$

1 combination is possible.

Question 2:

Three singers are taken from a set of 7, and four dances from a set of 10, hence:

$T = C_{7,3}C_{10,4} = \frac{7!}{3!4!} \times \frac{10!}{4!6!} = 245$

There are 245 ways to group them.

More can be learned about the combination formula at brainly.com/question/25821700

6 0

2 years ago