Answer : The mass of a sample of water is, 888.89 grams
Explanation :
Latent heat of vaporization : It is defined as the amount of heat energy released or absorbed when the liquid converted to vapor at atmospheric pressure at its boiling point.
Formula used :
where,
q = heat = 2000 kJ = 
(1 kJ = 1000 J)
L = latent heat of vaporization of water = 
m = mass of sample of water = ?
Now put all the given values in the above formula, we get:
(1 kg = 1000 g)
Therefore, the mass of a sample of water is, 888.89 grams
Mass m = 25 Kg; Force = Weight = mg Force = ma but a = g
F = 40.8 N
Required: gravity g = ?
F = mg
g = F/m
g = 40.8 N/25 Kg
g = 1.6 m/s²
Should be scientific theory
D- cation, When an atom loses a electron it becomes an ion but the result is called a cation. Then when electrons are gained it’s a anion.
Answer:
The frequency heard by the observer is 2760.73 hertz. Explanation:
Frequency of source, f = 2640 Hz
Velocity of source, 
The speed of sound, v = 343 m/s
Let f' is the frequency heard by the observer. According to Doppler's effect, the frequency of the observer is given by :
(as the source is moving towards observer)
f' = 2760.73 Hz
So, the frequency heard by the observer is 2760.73 hertz. Hence, this is the required solution.
