According to Einstein's famous formula, the relationship between mass and energy can be written E = M ∙ c2, where E = energy in joules, m = mass in kilograms and c = speed of light in meters per second. Sweden's annual energy use amounts to approximately 1.35 ∙ 10 up tp 18J. Suppose that all this energy could be created by converting matter into energy. If so, how much mass would be needed to cover the country's annual energy use? The speed of light is 3 ∙ 10 up to 8 m / s

the amount of mass needed is:  4.5 10^9 kg

Explanation:

Use the given equation:

E = m * c^2

with E = 1.35 * 10^(18)  J

and c = 3 * 10^8 m/s

and solve for the mass as shown below:

m = 1.35 * 10^(18) / 3 * 10^8 ≈ 4.5 10^9 kg

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.