Answer:
wait what do you mean? And why is this in physics?
Is this about the iron dome or something biblical?
Explanation:
Potential energy = mgh
Potential energy = 10 x 9.8 x 1.3
Potential energy = 127.4 J
It is called surface tension it is the elastic personality of some liquids as they pull together to take up as little surface area as possible. the water molecules would rather stay together than be pulled apart<span />
Answer:
14.43° or 0.25184 rad
Explanation:
v = Speed of sound in air = 343 m/s
f = Frequency = 1240 Hz
d = Width in doorway = 1.11 m
Wavelength is given by

In the case of Fraunhofer diffraction we have the relation

The minimum angle relative to the center line perpendicular to the doorway will someone outside the room hear no sound is 14.43° or 0.25184 rad