Thermal energy quantifies the amount of heat present in the body and is calculated through the equation,
H = mcpdT
where H is the heat, m is the mass, cp is the specific heat, and dT is the temperature difference. If all things are constant, and the thermal energy is halved then, dT should also be reduced to half.
Longitudinal waves transfer energy parallel to the direction of the wave motion
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.
The first one. The E and B chatacteristic are perpendicular to eachother. The direction of the wave can be found by the right hand rule.