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Zielflug [23.3K]
3 years ago
14

For every 21 litres of petrol a car can run for 80 km. How much petrol do you need (to 1 DP) to ensure the car has enough petrol

of a trip that is 224 km?
Mathematics
1 answer:
geniusboy [140]3 years ago
5 0

Answer:

1

Step-by-step explanation:

You might be interested in
find the area of this figure. round your answer to the nearest hundredth.use 3.14 to approximate pi.​
lord [1]

The area of the geometry is the sum of the area of the triangle and the semicircle will be 49.12 square feet.

<h3>What is Geometry?</h3>

It deals with the size of geometry, region, and density of the different forms both 2D and 3D.

The geometry is the combination of the semicircle and right triangle.

Then the area of the geometry will be

Area = 1/2 x 6 x 8 + π/8 x 8²

Area = 4 x 6 + 3.14 x 8

Area = 24 + 25.12

Area = 49.12 square feet

More about the geometry link is given below.

brainly.com/question/7558603

#SPJ1

5 0
2 years ago
A tank with a capacity of 500 gal originally contains 200 gal of water with 100 lb of salt in the solution. Water containing1 lb
devlian [24]

Answer:

(a) The amount of salt in the tank at any time prior to the instant when the solution begins to overflow is \left(1-\frac{4000000}{\left(200+t\right)^3}\right)\left(200+t\right).

(b) The concentration (in lbs per gallon) when it is at the point of overflowing is \frac{121}{125}\:\frac{lb}{gal}.

(c) The theoretical limiting concentration if the tank has infinite capacity is 1\:\frac{lb}{gal}.

Step-by-step explanation:

This is a mixing problem. In these problems we will start with a substance that is dissolved in a liquid. Liquid will be entering and leaving a holding tank. The liquid entering the tank may or may not contain more of the substance dissolved in it. Liquid leaving the tank will of course contain the substance dissolved in it. If <em>Q(t)</em> gives the amount of the substance dissolved in the liquid in the tank at any time t we want to develop a differential equation that, when solved, will give us an expression for <em>Q(t)</em>.

The main equation that we’ll be using to model this situation is:

Rate of change of <em>Q(t)</em> = Rate at which <em>Q(t)</em> enters the tank – Rate at which <em>Q(t)</em> exits the tank

where,

Rate at which <em>Q(t)</em> enters the tank = (flow rate of liquid entering) x (concentration of substance in liquid entering)

Rate at which <em>Q(t)</em> exits the tank = (flow rate of liquid exiting) x (concentration of substance in liquid exiting)

Let C be the concentration of salt water solution in the tank (in \frac{lb}{gal}) and t the time (in minutes).

Since the solution being pumped in has concentration 1 \:\frac{lb}{gal} and it is being pumped in at a rate of 3 \:\frac{gal}{min}, this tells us that the rate of the salt entering the tank is

1 \:\frac{lb}{gal} \cdot 3 \:\frac{gal}{min}=3\:\frac{lb}{min}

But this describes the amount of salt entering the system. We need the concentration. To get this, we need to divide the amount of salt entering the tank by the volume of water already in the tank.

V(t) is the volume of brine in the tank at time t. To find it we know that at t = 0 there were 200 gallons, 3 gallons are added and 2 are drained, and the net increase is 1 gallons per second. So,

V(t)=200+t

Therefore,

The rate at which C(t) enters the tank is

\frac{3}{200+t}

The rate of the amount of salt leaving the tank is

C\:\frac{lb}{gal} \cdot 2 \:\frac{gal}{min}+C\:\frac{lb}{gal} \cdot 1\:\frac{gal}{min}=3C\:\frac{lb}{min}

and the rate at which C(t) exits the tank is

\frac{3C}{200+t}

Plugging this information in the main equation, our differential equation model is:

\frac{dC}{dt} =\frac{3}{200+t}-\frac{3C}{200+t}

Since we are told that the tank starts out with 200 gal of solution, containing 100 lb of salt, the initial concentration is

\frac{100 \:lb}{200 \:gal} =0.5\frac{\:lb}{\:gal}

Next, we solve the initial value problem

\frac{dC}{dt} =\frac{3-3C}{200+t}, \quad C(0)=\frac{1}{2}

\frac{dC}{dt} =\frac{3-3C}{200+t}\\\\\frac{dC}{3-3C} =\frac{dt}{200+t} \\\\\int \frac{dC}{3-3C} =\int\frac{dt}{200+t} \\\\-\frac{1}{3}\ln \left|3-3C\right|=\ln \left|200+t\right|+D\\\\

We solve for C(t)

C(t)=1+D(200+t)^{-3}

D is the constant of integration, to find it we use the initial condition C(0)=\frac{1}{2}

C(0)=1+D(200+0)^{-3}\\\frac{1}{2} =1+D(200+0)^{-3}\\D=-4000000

So the concentration of the solution in the tank at any time t (before the tank overflows) is

C(t)=1-4000000(200+t)^{-3}

(a) The amount of salt in the tank at any time prior to the instant when the solution begins to overflow is just the concentration of the solution times its volume

(1-4000000(200+t)^{-3})(200+t)\\\left(1-\frac{4000000}{\left(200+t\right)^3}\right)\left(200+t\right)

(b) Since the tank can hold 500 gallons, it will begin to overflow when the volume is exactly 500 gal.  We noticed before that the volume of the solution at time t is V(t)=200+t. Solving the equation

200+t=500\\t=300

tells us that the tank will begin to overflow at 300 minutes. Thus the concentration at that time is

C(300)=1-4000000(200+300)^{-3}\\\\C(300)= \frac{121}{125}\:\frac{lb}{gal}

(c) If the tank had infinite capacity the concentration would then converge to,

\lim_{t \to \infty} C(t)=  \lim_{t \to \infty} 1-4000000\left(200+t\right)^{-3}\\\\\lim _{t\to \infty \:}\left(1\right)-\lim _{t\to \infty \:}\left(4000000\left(200+t\right)^{-3}\right)\\\\1-0\\\\1

The theoretical limiting concentration if the tank has infinite capacity is 1\:\frac{lb}{gal}

4 0
3 years ago
How long an umbrella will fit in the bottom of a suitcase 1.5 feet by 2.5 feet
IRINA_888 [86]

Answer:

pointing towards the top

Step-by-step explanation:

1.5 feet long 2.5 feet wide the suitcase is so straight

HOPE OT HELPS

7 0
3 years ago
Which statements are true about the area of the
cupoosta [38]

Answer:

A=bh..I don't get for those numbers

7 0
3 years ago
How do you evaluate the expression to this problem 24 divided by (-4)+(-2) times (-5)
Tju [1.3M]

24/-30 would be the answer

8 0
3 years ago
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