Find volume of prism it’s on mathswatch I’m really stick someone helpppp

A fisherman traveled in a boat from point N upstream. After having traveled 6 km, he stopped rowing and 2 hour 40 min after firs

Nat2105 [25]

Answer:

The speed of the river's current is 4.5 km/hr.

Step-by-step explanation:

Given : A fisherman traveled in a boat from point N upstream.

After having traveled 6 km, he stopped rowing and 2 hour 40 min after first leaving N, he was brought back to N by the current.

Knowing that the speed of the boat in still water is 9 km/hour

To find : The speed of the river’s current.

Solution :

Let the speed of current = x km/h

Speed of boat = 9 km/h

Thus, the speed in upstream = (9 - x) km/h

Also, the speed in downstream = x km/h (because the boat is stationary in downstream)

Total distance = 6 km ( from N to the point he reached )

Total time = 2 hours 40 minutes

$\text{2 hours 40 minutes}=2\frac{40}{60}=2 \frac{2}{3} \\\\\text{2 hours 40 minutes}=\frac{8}{3} \text{ hours}$

We know, $\text{Time} = \frac{\text{Distance}}{\text{Speed}}$

According to the question,

$\frac{6}{9-x}+\frac{6}{x}=\frac{8}{3}$

Taking LCM and 6 common

$6[\frac{x+9-x}{(9-x)x}]=\frac{8}{3}$

Take 6 to another side,

$\frac{9}{9x-x^2}=\frac{8}{3\times 6}$

Cross multiply,

$9\times 18=8\times(9x-x^2)$

$162=72x-8x^2$

Taking 4 common and cancel out

$4x^2-36x+81=0$

Solve quadratic equation by middle term split,

$4x^2-18x-18x+81=0$

$2x(2x-9)-9(2x-9)=0$

$(2x-9)(2x-9)=0$

$\Rightarrow 2x-9=0$

$\Rightarrow x=\frac{9}{2}=4.5$

Therefore, The speed of the river's current is 4.5 km/hr.

6 0

3 years ago

Two planes leave an airport at noon. If the eastbound plane flies at 660 mph and the westbound plane flies at 600 mph, at what t

Eddi Din [679]

I'm guessing that they took of in the same airport.

Each hour they will separate by 1260 miles or 21 miles each minute

2,000/21 = 95.23 minutes which is 1 hour and 35 minutes

Hope this helps :)

6 0

3 years ago

What is 1,144,646 rounded to the nearest million

marta [7]

Answer:

1,000,000

Step-by-step explanation:

8 0

4 years ago

Read 2 more answers

Si Martha retira de su cuenta el 10% para los transportes del mes. ¿Cuál es el nuevo saldo de la cuenta?

notsponge [240]

Respuesta:

0,9 veces

Explicación paso a paso:

Deje que la cantidad en la cuenta de Martha se denote como x, que es la cantidad en la cuenta = x

Porcentaje retirado para transporte = 10%

El porcentaje total siempre será del 100%

Por lo tanto, si se retira el 10%, entonces; el porcentaje restante es:

Porcentaje total: porcentaje gastado en transporte

(100% - 10%) * monto en cuenta

90% * x = 0,9 * x = 0,9x

Saldo de cuenta nueva = 0.9x

8 0

3 years ago

Dee Wallace's salary was $61,000 in 2006 and increased to $64,300 in 2009.

velikii [3]

Answer:

$1,100

Step-by-step Explanation:

Dee Wallace's salary in 2006 = $61,000 Dee Wallace's salary in 2009 = $64,300

The salary increased in => 2009 - 2006 = 3yrs

The amount of salary increased = 64,300-61000 = $3,300

The annual change of salary = 3,300/3 = $1,100

4 0

2 years ago