Which describes why people on earth can see light from the stars in the sky that are so far away?
1 answer:
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We will start by finding the heat in state one through the thermal efficiency or efficiency of a thermal machine is a coefficient or dimensionless ratio calculated as the ratio of the energy produced (in an operating cycle) and the energy supplied to the machine. Mathematically it is the relationship between the work generated and the heat emanated.
So,
The total change of energy is equivalent to 4500J and this is equal by conservation of energy to the total change in heat. So:
Therefore the energy which is discharged to the lower temperature reservoir every cicle is 921.7J
Answer:
C. 1) No Change (4 sec) 2) 5.7 sec 3) 2.8 sec 4) No Change (4 sec)
Explanation:
Given that:
Period (T) = 4 s
1) If the mass is doubled.
The period of a pendulum is given by the formula:
where L is the length and g is the acceleration due to gravity.
From the formula, the period does not depend on the mass of the spring therefore if the mass is doubled the period does not change.
2) The string length is doubled
Given that:
if the length is doubled, the new spring length is 2L. Therefore the new period (T1) is given as:
3) The string length is halved
Given that:
if the length is halved, the new spring length is L/2. Therefore the new period (T1) is given as:
4) The amplitude is halved
From the formula, the period does not depend on the amplitude therefore if the amplitude is halved the period does not change.
Answer:
Explanation:
The magnetic field B inside long solenoid with current I is given as
where
N is number of turn of solenoids = 1140 turns
I is current that passes through solenoid
L is length along which current pass = 0.350 m
plugging value to get required value of current
Answer:
The observer hears a loud sound
Explanation:
In order to know if the observer hears a loud or a quiet sound, you need to know if there is a constructive or destructive interference between the sound waves of the loudspeakers.
You first calculate the distance between the observer and the loudspeakers.
The distances are given by:
d1: distance to loudspeaker A = 2.10m
d2: distance to loudspeaker B
Next, you calculate the wavelength of the sound waves by using the following formula:
vs: speed of sound = 343 m/s
f: frequency of the waves = 400Hz
λ: wavelength
Next, you calculate the path difference between the distance from the observer to the loudspeakers:
You obtain a constructive interference (loud sound) if the quotient between the wavelength of the sound and the difference path is an integer:
Then, there will be a constructive interference, and the sound who the observer hears is loud.