Answer:
Specific heat of liquid 
Explanation:
We know in thermal equilibrium :
Loss in heat by iron block = Gain in heat by liquid .
Specific heat of iron = 0.45
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Now , loss in heat by iron block = 
Heat gain by liquid=
Equating both we get :

Answer:
The mass of the planet is 
Explanation:
Given that,
Time period = 42 hours = 151200 sec
Orbital radius = 0.002819 AU = 421716397.5 m
Mass of moon 
We need to calculate the mass of the planet
Using Kepler’s third law


Where, a = orbital radius
T = time period
G = gravitational constant
M = mass of moon
m = mass of planet
Put the value into the formula





Hence, The mass of the planet is 
Answer:
Frequency of sound wave = 198.83 hertz (Approx.)
Explanation:
Given:
Velocity of sound wave in air = 340 m/s
Wavelength = 1.71 meter
Find:
Frequency of sound wave
Computation:
Frequency = Velocity / Wavelength
Frequency of sound wave = Velocity of sound wave in air / Wavelength
Frequency of sound wave = 340 / 1.71
Frequency of sound wave = 198.8304
Frequency of sound wave = 198.83 hertz (Approx.)
Answer:
(C) They consist of ice.
Explanation:
Comet consist of a body of ice, rock and dust that can be several miles in diameter and orbits the sun. Debris from comets is the main source of many meteoroids.
The horizontal component of the force is 34.5 cos(45) = 24.4 newtons
The vertical component of the force is 34.5 sin(45) = 24.4 newtons