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3 years ago

Some one helppp!1.If there any real machine where its efficiency is 100%?why?

Physics

1 answer:

Salsk061 [2.6K]3 years ago

5 0

Answer:

No machine

Explanation:

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work). The output work is always less than the input work because some of the input work is used to overcome friction. Therefore, efficiency is always less than 100 percent.

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1. List the 3 major skeletal cartilages.

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Hyaline, elastic, & fibrocartilage!

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3 years ago

Read 2 more answers

Suppose that you are holding a pencil balanced on its point. If you release the pencil and it begins to fall, what will be the a

Naily [24]

Answer:

The angular acceleration of the pencil α = 17 rad·s⁻²

Explanation:

Using Newton's second angular law or torque to find angular acceleration, we get the following expressions:

τ = I α (1)

W r = I α (2)

The weight is that the pencil has is,

sin 10 = r / (L/2)

r = L/2(sin(10))

The shape of the pencil can be approximated to be a cylinder that rotates on one end and therefore its moment of inertia will be:

I = 1/3 M L²

Thus,

mg(L / 2)sin(10) = (1/3 m L²)(α)

α(f) = 3/2(g) / Lsin(10)

α = 3/2(9.8) / 0.150sin(10)

α = 17 rad·s⁻²

Therefore, the angular acceleration of the pencil is 17 rad·s⁻²

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3 years ago

Calculate earth's mass given the acceleration due to gravity at the north pole is 9.830 m/s2 and the mean radius of the earth at

valentinak56 [21]

Answer: $M = 5.98\times 10^{24} kg$

Explanation:

We know that force acting on an object due to Earth's gravity on the surface is given by:

$mg = G\frac{Mm}{r^2}\\ \Rightarrow g = \frac{GM}{r^2}$

where g is the acceleration due to gravity, r would be radius of Earth, M is the mass of Earth and G is the gravitational constant.

It is given that at pole, g = 9.830 m/s² and r = 6371 km = 6371 × 10³ m

$\Rightarrow M = \frac{g\times r^2}{G}$

$M = \frac{9.830 m/s^2 \times (6371 \times 10^3 m )^2}{6.67 \times 10^{-11} m^3 kg^{-1} s^{-2}}$

$\Rightarrow M = 5.98\times 10^{24} kg$

Hence, Earth's mass is $5.98\times 10^{24} kg$

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4 years ago

Which of the following best states the difference between a description and an explanation? A. A description is a statement that

rjkz [21]

It is C. A description goes into the details about something, and an explanation is a statement that clarifies something, generally a question.

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3 years ago

A spacecraft and a staellite are at diametrically opposite position in the same circular orbit of altitude 500 km above the eart

Tanya [424]

Answer:

Hello the diagram related to your question is attached below

answer: a) 851 m/s

b) 8506.1 secs

Explanation:

calculate the periodic time of the satellite using the equation below

t = $\frac{2\pi }{R} \sqrt{\frac{(R+h)^{3} }{g} }$ -- ( 1 )

where ; R = 6370 km

h = 500 km

g = 9.81 m/s^2

input given values into equation 1

t = 5670.75 secs

next calculate the periodic time taken by the space craft

a) determine the increase in speed

V = v - $\sqrt{\frac{gR^2}{R + h} }$

where ; v = 8463 m/s , R = 6370 km, h = 500 km

V = 851 m/s

b) Determine the periodic time for the elliptic orbit

τ = $\frac{3t}{2}$

= $\frac{3*5670.76}{2}$ = 8506.1 secs

attached below is the remaining part of the detailed solution

5 0

3 years ago

Some one helppp!1.If there any real machine where its efficiency is 100%?why?​

Some one helppp!1.If there any real machine where its efficiency is 100%?why?