Answer:
Therefore the surface area of the balloon is increased at 4 cm³/s.
Explanation:
The balloon is being filled with air at a rate of 10 cm³/s
It means the volume of the balloon is increased at a rate 10 cm³/s.
i.e 
Consider r be the radius of the balloon.
The volume of of a sphere is

Differentiate with respect to t



The surface of area of the balloon is(S) = 

Differentiate with respect to t


Putting the value of


Given that r = 5 cm
=4 cm³/s
Therefore the surface area of the balloon is increased at 4 cm³/s.
12 V is the f.e.m.

of the battery. The potential difference that is applied to the motor is actually the fem minus the voltage drop on the internal resistance r:

this is equal to the voltage drop on the resistance of the motor R:

so we can write:

and using

and

we can find the current I:
Answer:
=170kcal
Explanation:
We first calculate the amount of energy required to melt the alcohol using the formula: MLf, where Lf is the latent heat of fussion
We then calculate amount of heat required to raise the temperature of liquid alcohol to -14° C using MC∅. We then add the two.
Thus ΔH=MLf+MC∅
ΔH=2kg×25kcal/kg+ 2kg×(0.6kcal/kg.K×(-14-⁻114)
=50kcal+120kcal
=170kcal
<span>According to the concept of punctuated equilibrium, </span>new species evolve suddenly over relatively short periods of time (a few hundred to a thousand years), followed by longer periods in which little genetic change occurs. Hope this helps. Have a nice day.
Answer:
5.6*10^23. if 10^n is greater, that means its the larger value. hope dis helps
Explanation: