Answer:
The efficiency is 0.33, or 33%.
Explanation:
From the thermodynamics equations, we know that the formula for the efficiency of a heat engine is:
Where η is the efficiency of the engine, Q_1 is the heat energy taken from the hot source and Q_2 is the heat energy given to the cold object. So, plugging the given values in the formula, we obtain:
This means that the efficiency of the heat engine is 0.33, or 33% (The efficiency of an engine is dimensionless).
There's no such thing as "an unbalanced force".
If all of the forces acting on an object all add up to zero, then we say that
<span>the group </span>of forces is balanced. When that happens, the group of forces
has the same effect on the object as if there were no forces on it at all.
An example:
Two people with exactly equal strength are having a tug-of-war. They pull
with equal force in opposite directions. Each person is sweating and straining,
grunting and groaning, and exerting tremendous force. But their forces add up
to zero, and the rope goes nowhere. The <u>group</u> of forces on the rope is balanced.
On the other hand, if one of the offensive linemen is pulling on one end of
the rope, and one of the cheerleaders is pulling on the other end, then their
forces don't add up to zero, because even though they're opposite, they're
not equal. The <u>group</u> of forces is <u>unbalanced</u>, and the rope moves.
A group of forces is either balanced or unbalanced. A single force isn't.
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.
In question 1, both of your answers are correct, but I don't understand the process you went through in the 'a' part.
R = v/I . That's a correct formula.
But it doesn't help you in this form, because you need to find I
So turn it into a helpful form ... Solve it for I, so it says I=something.
R= v/I
Multiply each side by I : R I = V.
Now divide each side by R: I= V/R .
THERE'S the equation you want.
I = V / R
I = 1.5 / 10 = 0.15 Amp.
That's slightly cleaner, although I don't really understand what you were actually thinking in that part.
But again ... You answered both parts correctly, and your process in b is fine.
