What's the stuff called that holds a car window in place?

In the first stage of a two-stage Carnot engine, energy is absorbed as heat Q1 at temperature T1 = 500 K, work W1 is done, and e

Nataly [62]

Answer:

Efficiency = 52%

Explanation:

Given:

First stage

heat absorbed, Q₁ at temperature T₁ = 500 K

Heat released, Q₂ at temperature T₂ = 430 K

and the work done is W₁

Second stage

Heat released, Q₂ at temperature T₂ = 430 K

Heat released, Q₃ at temperature T₃ = 240 K

and the work done is W₂

Total work done, W = W₁ + W₂

Now,

The efficiency is given as:

$\eta=\frac{\textup{Total\ work\ done}}{\textup{Energy\ provided}}$

or

Work done = change in heat

thus,

W₁ = Q₁ - Q₂

W₂ = Q₂ - Q₃

Thus,

$\eta=\frac{(Q_1-Q_2)\ +\ (Q_2-Q_3)}{Q_1}}$

or

$\eta=1-\frac{(Q_1-Q_3)}{Q_1}}$

or

$\eta=1-\frac{(Q_3)}{Q_1}}$

also,

$\frac{Q_1}{T_1}=\frac{Q_2}{T_2}=\frac{Q_3}{T_3}$

or

$\frac{T_3}{T_1}=\frac{Q_3}{Q_1}$

thus,

$\eta=1-\frac{(T_3)}{T_1}}$

thus,

$\eta=1-\frac{(240\ K)}{500\ K}}$

or

$\eta=0.52$

or

Efficiency = 52%

8 0

3 years ago

Two wheels having the same radius and mass rotate at the same angular velocity. One wheel is made with spokes so nearly all the

Mazyrski [523]

Answer:

C. The wheel with spokes has about twice the KE.

Explanation:

Given that

Mass , radius and the angular speed for both the wheels are same.

radius = r

Mass = m

Angular speed = ω

The angular kinetic energy KE given as

$KE=\dfrac{1}{2}I\omega ^2$

I=Moment of inertia for wheels

Wheel made of spokes

I₁ = m r²

Wheel like a disk

I₂ = 0.5 m r²

Now by comparing kinetic energy

$\dfrac{KE_1}{KE_2}=\dfrac{I_1}{I_2}$

$\dfrac{KE_1}{KE_2}=\dfrac{mr^2}{0.5mr^2}$

$\dfrac{KE_1}{KE_2}=2$

KE₁= 2 KE₂

Therefore answer is C.

5 0

2 years ago

Please help! the mass of an object is measured on a pan balance with a precision of 0.005 g and the recorded value of 128.01 g.

inysia [295]

Yes, these two objects have different masses.

<h3>How can we calculate that this statement is right ?</h3>

To calculate the precision of mass we are using the formula,

Precision(P) = $\frac{m_1}{m_1+\triangle m}$

Or, $\triangle$ m= $\frac{m_1}{P}$ -m₁

For the first case we are given,

m₁= The recorded value of mass

= 128.01 g

P= Precision of the mass

=0.005g

So, according to the formula, $\triangle$ m will be,

$\triangle$ m= $\frac{128.01}{0.005}$ -128.01

Or, $\triangle$ m=25,473.99 g

Or, $\triangle$ m=25.47 Kg

For the first case $\triangle$ m is 25.47 Kg..

For the second case we are given,

m₁= The recorded value of mass

= 0.13 Kg

P= Precision of the mass

=0.005 Kg

So, according to the formula, $\triangle$ m will be,

$\triangle$ m= $\frac{0.13}{0.005}$ -0.13

Or, $\triangle$ m= 25.87 kg

For the second case $\triangle$ m is 25.87 Kg.

For the two cases $\triangle$ m has different values, 25.47 Kg≠25.87 Kg.

Therefore we can conclude that, these two objects have different masses.

Learn more about Mass:

brainly.com/question/3187640

#SPJ4

7 0

1 year ago

Is the term used to describe the removal of sand and soil by the wind.

Hitman42 [59]

Answer:

erosion

Explanation:

5 0

2 years ago

At a fixed depth within a fluid at rest, the pressure pushing upward is

earnstyle [38]

Answer: E) A) salt water.

Explanation:

E) In equilibrium, pressure exerts equally in all directions, so for a given depth, the pressure is the same for all points located at the same depth, and it can be written as follows:

p = p₀ + ρ.g.h, where p₀ = atmospheric pressure, ρ=fluid density, h=depth from the surface.

A) The buoyant force, as discovered by Archimedes, is an upward force, that opposes to the weight of an object (as it is always downward), and is equal to the weight of the volume of the liquid that the object removes, which means that is proportional to the density of the liquid.

As salt water is denser than fresh water, the buoyant force exerted by the salt water is always greater than the one produced by the fresh water, so objects will float more easily in salt water than in fresh water.

In the limit, it is possible that one object float in salt water and sink in fresh water.

3 0

3 years ago