Sun21November0420PM 10

A derived Le Système international d'unités (SI) unit of measurement is expressed as kg·m2·s-2

Which of the following derived units of measurement are expressed in this way?

(Please select 1 option)

Power

Force Incorrect answer selected

Energy This is the correct answer

Pressure

Velocity

Explanation

The newton (N) is the derived SI unit of force. It is the force required to move 1 kg of mass at a rate of one metre per second squared (m/s2):

F = m·a (where a is acceleration)

F = 1 kg·m/s2

The joule (J) is the derived unit of energy, work or amount of heat. It is the amount of energy expended if a force of one newton (N) is applied through a distance of one metre (N·m):

J = 1 kg·m/s2·m =

J = 1 kg·m2/s2 or 1 kg·m2·s-2

Velocity is metres travelled per second (m/s or m·s-1).

The SI unit of power is the watt (W) or number of joules expended per second:

J/s = kg·m2·s-2/s

J/s = kg·m2·s-3

Pressure is force (N) per unit area (m2) and measured is pascal (Pa):

Pa = kg·m·s-2/m2

Pa = kg·m-1·s-2

Answer Statistics

1

24%

2

33%

3

18%

4

11%

5

17%

Times answered: 254