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3 years ago

good morning to you all! can someone please answer this, ill give you brainliest and your earning 50 points.

Physics

2 answers:

elena55 [62]3 years ago

7 0

Despite the risks, Human populations can be found near volcanoes. This can be associated with the availability of which natural resource?

Geothermal energy

Geothermal energy is the form of energy obtained from the heat of the earth. Near volcanoes the land is more hot compared to the normal areas. So, the heat of the lava will help in producing Geothermal energy...~

otez555 [7]3 years ago

5 0

Answer:

Geothermal energy

Explanation:

The volcanoes erupt the hot magma or lava
This is the main source of geothermal energy.
As energy is most important thing for survival so many humans establish community near volcanoes

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Cloud [144]

Vibrations with troughs like a light wave

when you touch something that is stringy and wet/dry and move the object acts like a slinky of some sort

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3 years ago

A 3.5 kW drill transfers 5 000 kJ of kinetic energy during 15 seconds of use. What is the percentage efficiency of the drill?

Marizza181 [45]

Answer:

1.04%

Explanation:

Given that,

The power of drill = 3.5 kW = 3500 W

Transferred kinetic energy = 5000 kJ during 15 seconds of use.

We need to find the percentage efficiency of the drill. It can be given by :

$\eta=\dfrac{P_o}{P_i}\times 100$

Where

Po and Pi are output and input powers.

$P_o=\dfrac{5000\times 10^3}{15}\\\\=3.34\times 10^5\ W$

So,

$\eta=\dfrac{3500}{3.34\times10^{5}}\times100\\\\=1.04\%$

So, the percentage efficiency of the drill is 1.04%.

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3 years ago

What temperature is required to transfer waste heat to the environment for a heat engine to be 100 percent efficient?

OLEGan [10]

This can be seen as a trick question because heat engines can typically never be 100 percent efficient. This is due to the presence of inefficiencies such as friction and heat loss to the environment. Even the best heat engines can only go up to around 50% efficiency.

6 0

3 years ago

Read 2 more answers

A potter's wheel is spinning with an initial angular velocity of 11 rad/s . It rotates through an angle of 80.0 rad in the proce

Grace [21]

The angular acceleration of the wheel approximately -0.76 rad/s² or proportionally as deceleration approximately 0.76 rad/s.
It need approximately 14.474 s to come to rest.

<h2>Introduction</h2>

Hi ! I will help you to discuss about Proportionally Changes in Circular Motion. The analogy of proportionally changes in circular motion is same as the analogy of proportionally changes in direct motion. Here you will hear again the terms acceleration and change in speed, only expressed in the form of a certain angle coverage. Before that, in circular motion, it is necessary to know the following conditions:

1 rotation = 2π rad
1 rps = 2π rad/s
1 rpm = $\sf{\frac{1}{60} \: rps}$ = $\sf{\frac{1}{30}\pi \: rad/s}$

<h2>Formula Used</h2>

The following equations apply to proportionally changes circular motion:

<h3>Relationship between Angular Acceleration and Change of Angular Velocity </h3>

$\boxed{\sf{\bold{\omega_t = \omega_0 + \alpha \times t}}}$

With the following conditions:

$\sf{\omega_t}$ = final angular velocity (rad/s)
$\sf{\omega_0}$ = initial angular velocity (rad/s)
$\sf{\alpha}$ = angular acceleration (rad/s²)
t = interval of the time (s)

<h3>Relationship between Angular Acceleration and Change of $\sf{\theta}$ (Angle of Rotation) </h3>

$\boxed{\sf{\bold{\theta = \omega_0 \times t + \frac{1}{2} \times \alpha \times t^2}}}$

$\boxed{\sf{\bold{(\omega_t)^2= (\omega_0)^2 + 2 \times \alpha \times \theta}}}$

With the following condition :

$\sf{\theta}$ = change of the sudut (rad)
$\sf{\alpha}$ = angular acceleration (rad/s²)
t = interval of the time (s)
$\sf{\omega_t}$ = final angular velocity (rad/s)
$\sf{\omega_0}$ = initial angular velocity (rad/s)

<h2>Problem Solving</h2>

We know that :

$\sf{\omega_t}$ = final angular velocity = 0 rad/s >> see in the sentence "in the process of coming to rest."
$\sf{\omega_0}$ = initial angular velocity = 11 rad/s
$\sf{\theta}$ = change of the sudut = 80.0 rad

What was asked :

$\sf{\alpha}$ = angular acceleration = ... rad/s²
t = interval of the time = ... s

Step by step :

$\sf{\alpha}$ = ... rad/s²

$\sf{(\omega_t)^2= (\omega_0)^2 + 2 \times \alpha \times \theta}$

$\sf{0^2= (11)^2 + 2 \times \alpha \times 80}$

$\sf{0 = 121 + 160 \alpha}$

$\sf{-160 \alpha = 121}$

$\sf{\alpha = \frac{121}{-160}}$

$\sf{\alpha = -0.75625 \: rad/s^2 \approx \boxed{-0.76 \: rad/s^2}}$

t = ... s

$\sf{\alpha = \frac{\omega_0 - \omega_t}{t}}$

$\sf{-0.76 = \frac{0 - 11}{t}}$

$\sf{-0.76t = -11}$

$\sf{t = \frac{- 11}{-0.76}}$

$\boxed{\sf{t \approx 14.474 \: s}}$

<h3>Conclusion</h3>

So :

The angular acceleration of the wheel approximately -0.76 rad/s² or proportionally as deceleration approximately 0.76 rad/s.
It need approximately 14.474 s to come to rest.

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2 years ago

What types of cuts do jig saw sanders make?

LuckyWell [14K]

The jigsaw can be used to make both straight and curved cuts in a wide variety of materials, including wood, particleboard, plywood, plastic, metal, even ceramic tile. There is also way more than those, but those are just the basics or common things. Hope this helps!

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3 years ago

Read 2 more answers