Answer:

Explanation:
Mass of the Sun = 
Amount of Hydrogen = 75% of Mass of Sun,
thus mass of Hydrogen (m) in the Sun is,

m = 
Speed of Light (c) = 
Thus, energy(E) produced if whole of hydrogen is converted into energy,
E = mc²



Answer:
speed is affected by the medium in wich the wave travels.
Explanation:
The speed of a wave is affected when traveling in different medium, depending on the medium in which the wave travels it can go faster or slower, or not even be able to travel in that medium.
For light waves, the denser the medium through which the wave travels, the slower it will go through it, as there is more resistance to the light particles.
And in waves like sound, which instead of particles is a vibration or disturbance in the medium, they travel faster in denser mediums such as metal, because the disturbance is transmitted more efficiently thanks to how close together that the particles are in the metal, This is why sound does not travel in a vacuum; there are not even particles to transmit the vibration.
Answer:
10⁴ Pa
Explanation:
When the tank is half filled ,
- Volume = 5m * 4m * 1m = 20m³
Also we know that ,
- Density of water = 10³ kg/ m³
Density = Mass/Volume
10³ kg/m³ = m/20m³
m = 2 * 10⁴ kg
So that ,
Weight = mg
F = 2*10⁴ × 10 N
F = 2 * 10⁵ N
And ,
Pressure = Force/Area
P = 2 *10⁵/ 5 * 4 Pa
P = 10⁴ Pa
When you reverse the direction of the current, the current loop generated by the magentic field is revered.