Question

Which expression correctly describes energy using SI units? A. 1 J=1kg•m^2/s^2 B. 1 J= 1kg•m/s^2 C. 1 J= 1kg• m/s D. 1 J= 1kg•m^2/s

Answer 1

A. 1 J=1kg•m^2/s^2

Step-by-step explanation:

Energy refers to the capacity to do work. According to the International System of units (SI units), energy is measured in Joules.

Energy is represented by the force applied over a distance. Force is measured in Newton (N) and distance in metres (m). Hence, energy is Newton × metre (N.m)

Newton is derived from the SI units of mass (Kilograms), and acceleration (metres per seconds^2) i.e Kg.m/s^2, since Force = mass × acceleration.

Since; Energy = Newton × metres

If Newton = Kg.m/s^2 and metres = m

Energy (J) will therefore be; Kg.m/s^2 × m

1J = Kg.m^2/s^2