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:
Base units are defined units based on specific objects or events in the physical world. Derived units are defined by combining base units.
Base units are defined by a particular process of measuring a base quantity whereas derived units are defined as algebraic combinations of base units. For example, length is a base quantity in both SI and the English system, but the meter is a base unit in the SI system only.
E = mc²
E = 0.235 kg · (3×10⁸ m/s)² = 0.235 · 9×10¹⁶ kg·m/s²
E = 2.115×10¹⁶ J
The answer is d) 2.12×10¹⁶ J
Given:
Horizontal distance between two boats = x = 14 m
One boat is at trough, the other is at crest.
As there is no crests between them meaning the boat are next to each other.
Wavelength is the distance between two consecutive crests/troughs = w
The distance between a crest and a trough next to it = w/2
Complete cycles = c = 5
Time taken for c cycles = t = 15 s
Vertical distance between two boats = y = 2.4 m
To find:
wavelength = w = 2x = 28 m
Amplitude = A = Displacement from mean to extreme position = y/2 = 1.2 m
Time period for one cycle = T = t/c = 15/5 = 3 s/cycle
frequency = 1/T = 1/3 = 0.33 hertz
speed = wavelength/Period = w/T = 28/3 = 9.33 m/s