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3 years ago

Which of the following best represents the average speed of a fast runner?

2 answers:

8 0

the one above is incorrect the real answer is 10 meters per second and you don't really need an equation for this (it's pretty obvious ) :)

Tpy6a [65]3 years ago

3 0

For the answer to the question above, the easiest way to determine is changing every runner's speed into the same unit.

First = 10 m/s 

Second = 10 miles/min = 16090.34 / 60 m/s (As 1 mile = 1609.34 meter and 1 min = 60 sec) 
Second = 260.82 m/s 

Third = 10 cm/hr = 10*(0.01)/60*60 (As 1 cm = 0.01 m and 1 hr = 60*60 sec) 
Third = 0.000028 m/s 

Fourth = 10 km/sec = 10*1000 m/s (As 1 km = 1000 m and time is already in sec) 
Fourth = 10000 m/s 

So fastest would be the one who covers the largest distance in 1 sec. It would be the fourth one.

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Pls i need help in this

timurjin [86]

It’s a blank screen .. what’s the question ?

7 0

3 years ago

Find the maximum value or minimum value for the function f(x) = 0.15(x + 1)² - 3.

il63 [147K]

Answer:

The minimum value for $f(x) = 0.15(x + 1)^2 - 3$ is $-3$ .

Step-by-step explanation:

Given function is $f(x) = 0.15(x + 1)^2 - 3$

We need to find the maximum value or the minimum value for the function.

Now, differentiate $f(x) = 0.15(x + 1)^2 - 3$ w.r.t $x$ .

$f'(x) =\frac{d}{dx}(0.15(x + 1)^2 - 3)\\f'(x)=\frac{d}{dx}(0.15(x+1)^2-\frac{d}{dx}(3)\\$

$f'(x)=2\times 0.15(x+1)\frac{d}{dx}(x+1)-0\\f'(x)=0.3(x+1)(1)\\f'(x)=0.3(x+1)$

Now, we will equate $f'(x)=0$ to find critical point.

$0.3(x+1)=0\\x=-1$

Plug this critical point in to the function $f(x) = 0.15(x + 1)^2 - 3$ we get,

$f(-1) = 0.15(-1 + 1)^2 - 3\\f(-1)=-3$

Also, $f''(x)=0.3$ which is positive, We have minimum value.

So, the minimum value for $f(x) = 0.15(x + 1)^2 - 3$ is $-3$ .

7 0

3 years ago

A library building is in the shape of a rectangle. Its floor has a length of (3x + 5) meters and a width of (5x − 1) meters. The

malfutka [58]

We can use the Front Outside Inside Last (FOIL) method to expand the double bracket

$(3x+5)(5x-1)$

Front ⇒ $(3x)(5x)=15 x^{2}$
Outside ⇒ $(3x)(-1)=-3x$
Inside ⇒ $(5)(5x)=25x$
Last ⇒ $(5)(-1)=-5$

Put the four terms together we have
$15 x^{2} -3x+25x-5$ , then collect like terms
$15 x^{2} +22x-5$

5 0

3 years ago

Read 2 more answers

4. Find the solution of y = 2x + 5 for x = 1. A (1, 7) B (3, 1) C (1, 12) D (1, -2)

Sati [7]

Answer:

Step-by-step explanation:

4 0

3 years ago

A bag contains 4 red and 6 green gumballs. if you select 5 of them without looking, how many ways can you get exactly 3 red or e

marusya05 [52]

This is a combination problem. The approach to this is by using the nCr method, where n is the number of total objects and r is the number of success. For example, if you want to get 3 red out of the total 4, then that would be 4C3. That means,

4C3 = 4!/3!(4 - 3)! = 4 ways

If you want to get 2 green out of the total 6, then that would be 6C2. That means,

6C2 = 6!/2!(6-2)! = 15 ways

Therefore, there are a total of 4+15 = 19 ways.

8 0

3 years ago