A space station rotates, providing 1 g acceleration for its inhabitants. If it is

An inventor claims to have invented a heat engine that receives 750kJ of heat from a source at 400K and produces 250kJ of net wo

IRISSAK [1]

Answer:

the claim is not valid or reasonable.

Explanation:

In order to test the claim we will find the maximum and actual efficiencies. maximum efficiency of a heat engine can be found as:

η(max) = 1 - T₁/T₂

where,

η(max) = maximum efficiency = ?

T₁ = Sink Temperature = 300 K

T₂ = Source Temperature = 400 K

Therefore,

η(max) = 1 - 300 K/400 K

η(max) = 0.25 = 25%

Now, we calculate the actual frequency of the engine:

η = W/Q

where,

W = Net Work = 250 KJ

Q = Heat Received = 750 KJ

Therefore,

η = 250 KJ/750 KJ

η = 0.333 = 33.3 %

η > η(max)

The actual efficiency of a heat engine can never be greater than its Carnot efficiency or the maximum efficiency.

<u>Therefore, the claim is not valid or reasonable.</u>

3 0

3 years ago

We see a full moon by reflected sunlight. How much earlier did the light that enters our eye leave the sun? the earth-moon and e

Tju [1.3M]

The time taken by the light reflected from sun to reach on earth will be 8.4 minutes.

To find the answer, we need to know about the distance travelled by light.

<h3>How to find the time taken by the light reflected from sun to reach on earth?</h3>

So, in order to solve this problem, we must first know how far the moon is from Earth and how far the Sun is from the moon.
These distances are given as 3.8×10^5 km (Earth-Moon) and 1.5×10^8 km (Sun- Earth).
Since the Moon and Sun are on opposite sides of Earth during a full moon, the light's distance traveled equals,

$d=(1.5*10^8km)+2(3.8*10^5km)=1.51*10^8km=1.51*10^{11}m$

As we know that light travels at a speed of 300,000 km per second. then, the time taken by the light reflected from sun to reach on earth will be,

$t=\frac{1.51*10^{11}}{3*10^8}=503.33 s\\t=\frac{503.33}{60}=8.4min$

Thus, the time it takes for the light from the Sun to reach Earth and be recognized as 8.4 minutes.

Learn more about distance here:

brainly.com/question/11495758

#SPJ4

6 0

1 year ago

Identify the subordinate clause and tell if it is used as a noun, adjective, or adverb. Click on the blue box until the correct

charle [14.2K]

The subordinate clause is "<span>who are loyal and industrious" and is used as an adjective to describe students.</span>

7 0

3 years ago

Most motorcycles could win a drag race against most cars. Use<br>Newton's 2nd law to explain this.

shutvik [7]

Answer:

is has be deducted that acceleration of an object depends only on the the mass of the object. car has a greater mass that a motorcycle.

Explanation:

the newton second law states that when a net force act on an object,the object accelerates in the direction of the net force. the acceleration is directly proportional to the net force and inversely to the mass.

mathematically, F = ma .......................... (eqn 1)

where, F = force, m=mass and a = acceleration

F = m(ΔV/t) .......................... (eqn 2)

acceleration =change in velocity divide time

t = time

v= velocity

Ft = mΔV

also a∝1/m

this same second can also mean the rate of change in momentum of an object is directly proportional to the resultant force.

Drag race is a function of acceleration, therefore, a car weighs more than a motorcycle.

the reason while motorcycle moves more faster than a car is due to the weight of the motorcycle as compare to the car. if the same acceleration is applied, and there weigth are difference, this will affect the force (causing an increased resultant force for the car), whereas time used will be affected.

for example:

a motorcycle has a weight 0f 181kg

a car has a weight 0f 1590kg

from a∝1/m

they both will moves at a different acceleration

the force will be different

Ft = mΔV

5 0

3 years ago

Astronomers are getting information about dark energy from

Thepotemich [5.8K]

The only way of telling about dark energy is our observation of how the universe has been expanding. It basically works the opposite as gravity, pushing things away from it. Thus, the closest answer would be D. The shape of galaxies in cluster galaxies.

6 0

3 years ago

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