The thermal efficiency of an engine is
where
W is the work done by the engine
Q is the heat absorbed by the engine to do the work
In this problem, the work done by the engine is W=200 J, while the heat exhausted is Q=600 J, so the efficiency of the machine is
Answer:
r₂ = 0.2 m
Explanation:
given,
distance = 20 m
sound of average whisper = 30 dB
distance moved closer = ?
new frequency = 80 dB
using formula
I₀ = 10⁻¹² W/m²
now,
to hear the whisper sound = 80 dB
we know intensity of sound is inversely proportional to square of distances
r₂ = 0.2 m
To solve this problem it is necessary to apply the definition of severity of Newtonian laws in which it is specified that gravity is defined by
Where
G= Gravitational Constant
M = Mass of Earth
R= Radius from center of the planet
According to the information we need to find the gravity 350km more than the radius of Earth, then
Therefore the gravitational acceleration at 350km is