An athlete needs to lose weight and decides to do it by “pumping iron.” (a) How many times must an 90.0 kg weight be lifted a di
1 answer:
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Answer:
True
The escape speed from the Moon is much smaller than from Earth.
Explanation:
The escape speed is defined as:
(1)
Where G is the gravitational constant, M is the mass and r is the radius.
The mass of the Earth is and its radius is
Then, replacing those values in equation 1 it is gotten.
For the case of the Moon:
Hence, the escape speed from the Moon is much smaller than from Earth.
Since it has a smaller mass and smaller radius compared to that from the Earth.
Answer:
Explanation:
We know,
..............(1)
where,
η = Efficiency of the engine
T₁ = Initial Temperature
T₂ = Final Temperature
Q₁ = Heat available initially
Q₂ = Heat after reaching the temperature T₂
Given:
η =0.280
T₁ = 3.50×10² °C = 350°C = 350+273 = 623K
Q₁ = 3.78 × 10³ J
Substituting the values in the equation (1) we get
or
or
⇒
Now,
The entropy change () is given as:
or
substituting the values in the above equation we get