The balloon will shrink because the average kinetic energy of gas molecules in a balloon decreases with fall in temperature. Butif we warm the balloon , it will rise.
MARK IT BRANLIEST PLZ..
To be able to answer this item, we are to calculate the power that the machine could deliver from hp to kW.
(45 hp)(746 W/1 hp) = 33570 W
Power is the amount of energy delivered at a certain period.
t = (6.20 x 10^2 J)/ (33570 kJ/s)
t = 0.01845 s
The complete question is how much heat energy is delivered by the iron in 30 seconds.
Heat is given by IVt, Where I is the current in Amperes, V is the voltage, and t is the time in seconds,
Therefore;
Heat energy = 120 × 10 ×30
= 36000 joules or 36 kJ
Heat energy is measured in joules.
The speed of a electron that is accelerated from rest through an electric potential difference of 120 V is 
<h3>
How to calculate the speed of the electron?</h3>
We know, that the energy of the system is always conserved.
Using the Law of Conservation of energy,
U=0
Here, K is the kinetic energy and U is the potential energy.
Now, substituting the formula of U and K, we get:
=0------(1)
Here,
m is the mass of the electron
v is the speed of the electron
q is the charge on the electron
V is the potential difference
Let
and
represent the final and initial speed.
Here,
=0
Solving for
, we get:


=6.49
m/s
To learn more about the conservation of energy, refer to:
brainly.com/question/2137260
#SPJ4