W work
F force
s distance
If F = constant:
W₁ = F·s
If you triple the force and the distance:
W₂ = 3F · 3s = 9 F·s = 9 W₁
<u>Given;</u>
mass m = 75 kg
acceleration a = 24.5 ms²
<em>F = ma </em>
F = 75 kg * 24.5 ms²
= 1837.5 kg ms².
Despite current has a magnitude and a direction, like vectors, it is a scalar because it doesn't obey laws of vector addition. For instance, if we consider a junction of

in a circuit, and two currents entering this junction, we know that the resultant current is just the algebraic sum of the two currents, not the vector sum, so it is not a vector quantity.
The absolute simplest way to explain E=MC^2 is: a lot of energy from a little mass.