Answer:
13.7%
Explanation:
Given that,
Heat absorbed by the engine = 97.2 kJ
Heat exhausted by the engine in each cycle = 83.8 kJ
We need to find the efficiency of the engine. It is calculated by the formula.

so, the efficiency of heat engine is 13.7%.
Answer:
The drift speed of the electrons in the wire is 2.12x10⁻⁴ m/s.
Explanation:
We can find the drift speed by using the following equation:
Where:
I: is the current = 4.50 A
n: is the number of electrons
q: is the modulus of the electron's charge = 1.6x10⁻¹⁹ C
A: is the cross-sectional area = 2.20x10⁻⁶ m²
We need to find the number of electrons:
Now, we can find the drift speed:
Therefore, the drift speed of the electrons in the wire is 2.12x10⁻⁴ m/s.
I hope it helps you!
Answer:
Wavelength of the sound wave that reaches your ear is 1.15 m
Explanation:
The speed of the wave in string is

where T= 200 N is tension in the string ,
=1.0 g/m is the linear mass density


Wavelength of the wave in the string is

The frequency is

The required wavelength pf the sound wave that reaches the ear is( take velocity of air v=344 m/s)

Answer:
The answer should be A and B. I don't fully know so don't quote me on that! Haha.
Explanation: