What is the distance between -10 and 9? 1.-8 2.-14 3.-19 4.-15

In the 2010 Winter Olympics, the American speed skater Apolo Ohno won the silver medal in the 1,500 meter race. How many kilomet

bogdanovich [222]

1000 meters= 1 kilometer so your answer is 1.5 kilometers

5 0

3 years ago

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A firework is launched at the rate of 10 feet per second from a point on the ground 50 feet from an observer. to 2 decimal place

Kazeer [188]

The rate of change of the angle of elevation when the firework is 40 feet above the ground is 0.12 radians/second.

First we will draw a right angle triangle ΔABC, where ∠B = 90°

Lets, assume the height(AB) = h and base(BC)= x

If the angle of elevation, ∠ACB = α, then

tan(α) = $\frac{AB}{BC} = \frac{h}{x}$

Taking inverse trigonometric function, α = tan⁻¹ ( $\frac{h}{x}$ ) .............(1)

As we need to find the rate of change of the angle of elevation, so we will differentiate both sides of equation (1) with respect to time (t) :

$\frac{d\alpha}{dt}=[\frac{1}{1+ \frac{h^2}{x^2}}]*(\frac{1}{x})\frac{dh}{dt}$

Here, the firework is launched from point B at the rate of 10 feet/second and when it is 40 feet above the ground it reaches point A,

that means h = 40 feet and $\frac{dh}{dt}$ = 10 feet/second.

C is the observer's position which is 50 feet away from the point B, so x = 50 feet.

$\frac{d\alpha}{dt}= [\frac{1}{1+ \frac{40^2}{50^2}}] *\frac{1}{50} *10\\ \\ \frac{d\alpha}{dt} = [\frac{1}{1+\frac{16}{25}}] *\frac{1}{5}\\ \\ \frac{d\alpha}{dt} = [\frac{25}{41}] *\frac{1}{5}\\ \\ \frac{d\alpha}{dt}= \frac{5}{41} =0.1219512$

= 0.12 (Rounding up to two decimal places)

So, the rate of change of the angle of elevation is 0.12 radians/second.

5 0

3 years ago

Help mehhhh plz ASAP

DanielleElmas [232]

Answer:75

Step-by-step explanation:2 1/2 is equal to 5 halves. If each half is equal to 15 then all you do is multiply 15 by 5

8 0

3 years ago

Find the value of x (click photo)

Zolol [24]

Answer:

x = 130 degrees

Step-by-step explanation:

7-sided polygon = 900 degrees

114 + 138 + 127 + 108 + 142 + 141 + x = 900

770 + x = 900

-770 -770

x = 130

Hope this helped! Have a nice day! Plz mark as brainliest!!!

-XxDeathshotxX

5 0

3 years ago

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What is the 24th term if the arithmetic sequence where a1 = 8 and a9 = 56

AnnyKZ [126]

Answer:

$a_{24} = 146$

Step-by-step explanation:

a1 = 8

a9 = 56

Using formula for finding nth term of arithmeric sequence

$a_{n} =a_{1} + (n-1)d$

We have to find 24th term, therefore n = 24

$a_{1}$ is the first term but we are missing d

d is the difference between the two consecutive terms, lets calculate it first

a9 = 56

Using the above given formula for finding d

put n = 9, a9= 56

$a_{9} =a_{1}+ (9-1)d$

56 = 8 + 8d

8d = 48

d = 6

Getting back to main part of finding 24th term

n = 24, d = 6, a1 = 8

put values in nth term formula

$a_{n} =a_{1}+ (n-1)d$

$a_{24} = 8 + (24-1)6$

$a_{24} = 8 + 138$

$a_{24} = 146$

5 0

3 years ago