Answer:
<h2>0.094 kg</h2>
Explanation:
Latent heat of vaporization of 
at 37°C is 
.
When the sweat on our body evaporates, it absorbs energy from our body to overcome it's Latent heat of vaporisation. Thus our body cools down when sweat evaporates.
So, Energy absorbed by sweat to evaporate = Energy lost by body
Specific heat capacity of human body = 
. Jogger weights 60.4 kg. Body temperature decreases by 
Energy absorbed from body = 
∴ 0.094 kg of sweat has evaporated from the body.
Answer:
d) 4a
Explanation:
r = Distance
Electrostatic force is given by
It can be seen that the force is inversely proportional to distance
If the distance is reduced
So, the new acceleration will be four times the old acceleration
The answer is d) 4a
1). The forces inside the atom are always, totally, completely, electrostatic forces. Those are so awesomely stronger than the gravitational forces that the gravitational ones are totally ignored, and it doesn't change a thing.
Parts 2 and 3 of this question are here to show us how the forces compare.
Part-2). The electrostatic force between a proton and an electron.
The constant in the formula is 9x10^9, and the elementary charge is 1.602 x 10^-19 Coulomb ... same charge on both particles, but opposite signs.
I worked through it 3 times and got 0.000105 N every time. So the best choice is 'C', even though we disagree by a factor of ten times. You'll see in part-3 that it really doesn't make any difference.
Part-3). Gravitational force between a proton and an electron.
The constant in Newton's gravity formula is 6.67x10^-11 . You'll have to look up the masses of the proton and the electron.
I got 2.163 x 10^-55 N ... exactly choice-C. yay !
Now, after we've slaved over a hot calculator all night, the thing that really amazes us is not only that the electrostatic force is stronger than the gravitational force, but HOW MUCH stronger ... 10^51 TIMES stronger. That's a thousand trillion trillion trillion trillion times stronger !
That's why it has no effect on the measurements if we just forget all about the gravitational forces inside the atom.
Carson's Rule says:
FM occupied bandwidth =
(2) · (Peak deviation + Highest modulating frequency)
so
FM bw = (2) · (60 kHz + 15 kHz)
FM bw = (2) · (75 kHz)
FM bw = 150 kHz
(I used to eat this stuff for lunch, but it's been almost 40 years. Thanks for taking me back. Those were the good old days.)
