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2 years ago

How do I complete this question on arc length?

Mathematics

2 answers:

tresset_1 [31]2 years ago

5 0

Answer:

v ≈ 8.5 km/h

Step-by-step explanation:

Since the diameter of the wheel is 3 m the radius will be r = 1.5 m.

Use the radius of the water wheel to find it's circumference C:

$C=2\pi r$ [set r = 1.5 m]

⇒ $C=2\pi (1.5)$

⇒ $C=3\pi$ m

One revolution of the water wheel corresponds to $3\pi$ meters so the angular velocity 15 rmp (revolutions per minute) corresponds to:

$15(3\pi )$ = $45\pi$ $m$ /min

Using this result, the speed of the river in kilometers per hour will be:

$v=\frac{45\pi m }{1 min}$ × $\frac{1 km}{1000 m}$ × $\frac{60 min}{1 h}$

⇒ $v=8.48230016469$ $km/h$

⇒ $v$ ≈ $8.5$ km/h

Nikolay [14]2 years ago

3 0

Answer:

≈ 8 km per hour

Step-by-step explanation:

C = $\pi$ d

C = $\frac{66}{7}$

Velocity = $\frac{66}{7}$ × 15 = $\frac{990}{7}$ ( meters per minute ) = $\frac{0.99}{7}$ × 60 ≈ 8.5 km/h

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It takes 32 hours for a motorboat moving downriver to get from pier A to pier B. The return journey takes 48 hours. How long doe

lina2011 [118]

Answer:

Time taken by the un powered raft to cover this distance is T = 192.12 hr

Step-by-step explanation:

Let speed of boat = u $\frac{km}{hr}$

Speed of current = v $\frac{km}{hr}$

Let distance between A & B = 100 km

Time taken in downstream = 32 hours

$32 = \frac{100}{u +v}$

$u + v = \frac{100}{32}$

u + v = 3.125 ------ (1)

Time taken in upstream = 48 hours

$48 = \frac{100}{u -v}$

$u -v = \frac{100}{48}$

u - v = 2.084 ------- (2)

By solving equation (1) & (2)

u = 2.6045 $\frac{km}{hr}$

v = 0.5205 $\frac{km}{hr}$

Now the time taken by the un powered raft to cover this distance

$T = \frac{100}{v}$

Because un powered raft travel with the speed of the current.

$T = \frac{100}{0.5205}$

T = 192.12 hr

Therefore the time taken by the un powered raft to cover this distance is

T = 192.12 hr

3 0

3 years ago

Read 2 more answers

Algebra II Help??? Subtracting Fractions (2x)/(y^2-x^2) - (x)/(y-x)

denis23 [38]

Make bottom number same

ok, so remember
(a-b)(a+b)=a²+b²
so

to get from (y-x) to (y²-x²), multiply 2nd fraction by (y+x)

so multiply 2nd fraction by (y+x)/(y+x)
$\frac{2x}{y^2-x^2}- \frac{(y+x)(x)}{y^2-x^2}$ =
$\frac{2x-x(x+y)}{y^2-x^2}$ =
$\frac{2x-x^2-xy}{y^2-x^2}$

4 0

2 years ago

Please help me!!!!!!!!!

nalin [4]

(y+20)=1(x+10); First, we can find the slope by using the equation y2-y1/x2-x1.

-9+20/1+10 (Accounting for double negatives).

11/11 = 1

The slope of the equation is 1, now we just need to pick a set of points from which we derived the slope from (doesn't matter which) as y1 and x1 in the point-slope equation. (y-y1)=m(x-x1)

Your final answer can either be (y+20)=1(x+10) or (y+9)=1(x-1) but in the context of this question it is (y+20)=1(x+10)

8 0

3 years ago

Find the HCF of x^2y and x

3241004551 [841]

The highest common factor of $x^2 y$ and $x$ is $\boxed{x}$