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3 years ago

A heat engine operating between the

Physics

1 answer:

Sophie [7]3 years ago

3 0

Answer:

(Q1 - Q2)/Q1

Explanation:

The efficiency of any device can be given by the following formula:

$Efficiency = \eta$ = Output/Input

Now, for engine the output is the mechanical work that it does and the input is the heat that it absorbs. Let:

W = Work Done by the engine

Q₁ = Heat Absorbed by the System

Q₂ = Heat Rejected by the System (Because According to 2nd Law of Thermodynamics, engine can not convert the entire heat into work without rejection of some heat)

Therefore, the equation becomes:

$\eta = \frac{W}{Q_{1}}$

but, the work can be written as the difference between the absorbed heat and the rejected heat. Hence,

$\eta = \frac{Q_{1} - Q_{2}}{Q_{1}}$

Therefore, the correct option is:

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Nio conducts a science experiment. He puts yeast into a bottle with water and sugar, and then caps the bottle with a balloon. He

KATRIN_1 [288]

Answer: Option (C) is the correct answer.

Explanation:

When yeast is added into a bottle with water and sugar then after some time yeast becomes activated. This results in the formation of a chemical change as bubbles are formed on the surface of the mixture in the bottle.

This indicates that a gas has been released due to the chemical change.

Thus, we can conclude that most likely a chemical change has occurred because a gas was produced.

3 0

4 years ago

Read 2 more answers

One star has a mass slightly more than the mass of the sun. Which of these graphs would best model and predict the lifetime of t

Oksanka [162]

Answer:

Explanation:

6 0

4 years ago

An object is realsed From rest . how far does it fall during the second second of fall?

Savatey [412]

Answer:

14.715 m

Explanation:

Assume that the acceleration due to gravity is 9.81 m/s^2 downwards, take downwards as positive

First second:

v = u + at

v = 9.81 m/s

Second second:

s = ut + (1/2)at^2

s = 9.81(1) + (1/2)(9.81)(1)^2

s = 14.715 m

6 0

3 years ago

In order for a space shuttle to leave Earth, it must produce a great amount of thrust. Its rocket boosters create this thrusting

bonufazy [111]

Answer:

Orbit

Explanation:

The term that describes motion of the shuttle around earth is called as<em> Orbit.</em>

The orbit is defined as a regular repeating path that object takes around another.

The shuttle circles around the earth at a constant distance from earth surface is because of earth gravity and forward motion of earth.

5 0

4 years ago

A freight car of mass M contains a mass of sand m. At t = 0 a constant horizontal force F is applied in the direction of rolling

Veronika [31]

Answer:

Amount of linear movement

Explanation:

Our system is defined by the rate of change in mass that

leaves the car $\Delta m_ {s}$ , this happens during a time interval

$[t, t + \Delta t]$ , in addition to freight car and sand at time t.

In this way we need to define the two states:

State 1,

consider $t, m_ {c} (t) + \Delta m_ {s}$ and V.

State 2,

consider $t + \Delta t, m_ {c} (t), V + V \Delta V$

In this state is the mass of sand output, which

is composed of

$\Delta m_{s}, V + \Delta V$

In this way we define the Linear movement in x, like this:

$p_ {x} (t) = (\Delta m_ {s} + m_ {c} (t)) v$

$p_ {x} (t+\Delta t) = (\Delta m_ {s} + m_ {c} (t)) (v + \Delta v)$

$m_ {c} (t) = m_ {c, 0} - bt = m_ {c} + m_ {s} -bt$

In this way we proceed to obtain the Force

$F =\lim_{\Delta t \rightarrow 0} \frac {p_x (t + \Delta t) -p_ {x} (t)} {\Delta t}$

$F = lim_{\Delta t \rightarrow 0} m_ {c} (t) \frac {\Delta v} {\Delta t} + lim_{\Delta t \rightarrow 0} m_ {s} (t) \frac {\Delta v} {\Delta T}$

Since the mass of the second term becomes 0, the same term is eliminated, thus,

$F = m_ {c} (t) \frac {dv} {dt}$

$\int\limit ^ {v (t)} _ {v = 0} dv = \int\limit^t_0 \frac{Fdt} {m_ {c} + m_ {s} -bt}$

$V (t) = - \frac {F} {b} ln (\frac {m_c + m_s-bt} {m_c + m_s})$

3 0

4 years ago