LAQ : Define (i) 1 joule, (ii) 1 newton, (iii) 1 nanosecond, (iv) 1 light year, (v) 1 μ, (vi) 1Å, (vii) 1 u (or amu)

Question 9

Define (i) 1 joule, (ii) 1 newton, (iii) 1 nanosecond, (iv) 1 light year, (v) 1 μ, (vi) 1Å, (vii) 1 u (or amu).

Answer

1. 1 joule is the amount of work done when a force of 1 newton is applied over a distance of 1 meter in the direction of the force.
2. 1 newton is the force required to accelerate a mass of 1 kilogram at a rate of 1 meter per second squared.
3. 1 nanosecond is a unit of time equal to one billionth of a second (10^-9 seconds).
4. 1 light year is the distance that light travels in one year, approximately equal to 9.46 trillion kilometres.
5. 1 μ (or micrometre) is a unit of length equal to one-millionth of a meter (10^-6 meters).
6. 1 Å (or angstrom) is a unit of length equal to one ten-billionth of a meter (10^-10 meters).
7. 1 u (or amu) is a unit of mass equal to one-twelfth of the mass of a carbon-12 atom, approximately equal to 1.66 × 10^-27 kilograms.