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3 years ago

8

The ____________is a metal retainer that keeps the rolling elements evenly spaced. N A. seal N B. separator N C. bearing N D out

er race

1 answer:

lana [24]3 years ago

3 0

Explanation:

N. B separator is the correct ande

You might be interested in

Find the wavelength of the balmer series spectral line corresponding to n = 15.

Anna71 [15]

Answer:

371.2 mm

Explanation:

The Balmer series of spectral lines is obtained from the formula

1/λ = R(1/2² -1/n²) where λ = wavelength, R = Rydberg's constant = 1.097 × 10⁷ m⁻¹

when n = 15

1/λ = 1.097 × 10⁷ m⁻¹(1/2² -1/15²)

= 1.097 × 10⁷ m⁻¹(1/4 -1/225)

= 1.097 × 10⁷ m⁻¹(0.25 - 0.0044)

= 1.097 × 10⁷ m⁻¹ 0.245556

= 2.693 10⁶ m⁻¹

So,

λ = 1/2.693 10⁶ m⁻¹

= 0.3712 10⁻⁶ m

= 371.2 mm

7 0

3 years ago

Problem 4 A meteoroid is first observed approaching the earth when it is 402,000 km from the center of the earth with a true ano

Nikitich [7]

Answer:

Part a: The eccentricity is 1.086.

Part b: The altitude at closest approach is 5088 km

Part c: The velocity at perigee is 8.516 km/s

Part d: The turn angle is 134.08 while the aiming radius is 5641.28 km

Explanation:

<h2>Part a </h2>

Specific energy is given by

$\epsilon=\frac{v^2}{2}-\frac{\mu}{r}$

Here

ε is the specific energy
v is the velocity which is given as 2.23 km/s
μ is the gravitational constant whose value is 398600
r is the distance between earth and the meteorite which is 402,000 km

$\epsilon=\frac{v^2}{2}-\frac{\mu}{r}\\\epsilon=\frac{2.2^2}{2}-\frac{398600}{402,000}\\\epsilon=1.495 km^2/s^2$

Value of specific energy is also given as

$\epsilon=\frac{\mu}{2a}\\a=\frac{\mu}{2\epsilon}\\a=\frac{398600}{2\times 1.495}\\a=13319 km$

Orbit formula is given as

$r=a(\frac{e^2-1}{1+ecos \theta})\\ae^2-recos\theta-(a+r)=0$

Putting values in this equation and solving for e via the quadratic formula gives

$ae^2-recos\theta-(a+r)=0\\(133319)e^2-(402000)(cos 150) e-(133319+402000)=0\\133319e^2+348142.21 e-535319=0\\\\e=\frac{-348142.21 \pm \sqrt{348142.21^2-4(133319)(535319)}}{2 (133319)}\\\\e=1.086 \, or \, -3.69$

As the value of eccentricity cannot be negative so the eccentricity is 1.086.

<h2>Part b</h2>

The radius of trajectory at perigee is given as

$r_p=a(e-1)\\$

Substituting values gives

$r_p=133319 (1.086-1)\\r_p=11465.4 km$

Now for estimation of altitude z above earth is given as

$z=r_p-R_E\\z=11465.4-6378\\z=5087.434\\z\approx 5088 km$

So the altitude at closest approach is 5088 km

<h2>Part c</h2>

radius of perigee is also given as

$r_p=\frac{h^2}{\mu}\frac{1}{1+e}$

Rearranging this equation gives

$h=\sqrt{r_p\mu(1+e)}\\h=\sqrt{11465.4 \times 3986000 \times (1+1.086)}\\h=97638.489 km^2/s$

Now the velocity at perigee is given as

$v_p=\frac{h}{r_p}\\v_p=\frac{97638.489}{11465.4}\\v_p=8.516 km/s\\$

So the velocity at perigee is 8.516 km/s

<h2>Part d</h2>

Turn angle is given as

$\delta =2 sin^{-1} (\frac{1}{e})$

Substituting value in the equation gives

$\delta =2 sin^{-1} (\frac{1}{e})\\\delta =2 sin^{-1} (\frac{1}{1.086})\\\delta =134.08$

Aiming radius is given as

$\Delta =a \sqrt{e^2-1}$

Substituting value in the equation gives

$\Delta =a \sqrt{e^2-1}\\\Delta =13319 \sqrt{1.086^2-1}\\\Delta=5641.28 km$

So the turn angle is 134.08 while the aiming radius is 5641.28 km

3 0

4 years ago

A 70.0 kg base runner moving at a speed of 4.0 m/s begins his slide into second base. The coefficient of friction between his cl

Andre45 [30]

Answer:

B. 560 J

J. 1.2 m

Explanation:

v = Final velocity = 0

u = Initial velocity = 4 m/s

$\mu$ = Coefficient of friction = 0.7

m = Mass of runner = 70 kg

g = Acceleration due to gravity = $9.81\ \text{m/s}^2$

Kinetic energy is given by

$K=\dfrac{1}{2}m(v^2-u^2)\\\Rightarrow K=\dfrac{1}{2}\times 70\times (0^2-4^2)\\\Rightarrow K=-560\ \text{J}$

The mechanical energy lost is 560 J

Acceleration is given by

$a=-\mu g\\\Rightarrow a=-0.7\times 9.81\\\Rightarrow a=-6.867\ \text{m/s}^2$

From kinematic equations we get

$v^2-u^2=2as\\\Rightarrow s=\dfrac{v^2-u^2}{2a}\\\Rightarrow s=\dfrac{0^2-4^2}{2\times -6.867}\\\Rightarrow s=1.165\approx 1.2\ \text{m}$

The runner slides for 1.2 m

4 0

3 years ago

Can someone please tell me the answer,I can't find the answer XD

Butoxors [25]

Acid rain is rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm, typically to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulfur and nitrogen oxides, which combine with atmospheric water to form acids.

7 0

4 years ago

Furkat [3]

So, the initial altitude of the parachuter is approximately <u>(C). 123 m</u>.

<h2>Introduction</h2>

Hi ! In this question, I will help you. In this question, you will learn about the fall time of the free fall motion. Free fall is a downward vertical motion without being preceded by an initial velocity. When moving in free fall, the following equations apply:

<h3>The equation for calculating the height (h)</h3>

$\boxed{\sf{\bold{h = \frac{1}{2} \cdot g \cdot t^2}}}$

<h3>The equation for calculating the time (s)</h3>

$\boxed{\sf{\bold{t = \sqrt{\frac{2 \cdot h}{g}}}}}$

<h3>The equation for calculating the velocity (v)</h3>

$\boxed{\sf{\bold{v = \sqrt{2 \times g \times h}}}}$

With the following condition :

t = interval of the time (s)
h = height or any other displacement at vertical line (m)
g = acceleration of the gravity (m/s²)
v = velocity (m/s)

<h2>Problem Solving</h2>

We know that :

t = interval of the time = 5 s
g = acceleration of the gravity = 9.81 m/s²

What was asked :

h = height or displacement at vertical line = ... m

Step by Step :

$\sf{h = \frac{1}{2} \cdot g \cdot t^2}$

$\sf{h = \frac{1}{2} \cdot 9.81 \cdot 5^2}$

$\sf{h = \frac{245.25}{2}}$

$\boxed{\sf{h = 122.625 \: m \approx 123 \: m}}$

<h3>Conclusion</h3>

So, the initial altitude of the parachuter is approximately 123 m (C.)

<h3>See More</h3>

Time that needed for hearing the splash of fallen rock in the well brainly.com/question/26485521
The speed of the object at a certain height (free fall motion) brainly.com/question/26377041
The relationship between acceleration and the change in velocity and time in free fall brainly.com/question/26486625

4 0

2 years ago