Theory:

In the previous exercises, we have discussed the basics of Units and SI units. In this exercise, we are going to look at the basics of derived units.
 
What are derived units?
A derived unit is a unit that results from a mathematical combination of SI base units.
SI is built on seven fundamental standards called base units. All other SI units are derived by multiplying, dividing or powering the base units in various combinations.
 
For example:
  • The area is length multiplied by width and has the unit of m2.
  • Mechanical work is a force applied, multiplied by the distance moved and has the unit newton metre. It is written as NmorJ.
  • Velocity is displacement divided by time and has the unit metre per second. It is written as ms1.
S. No.
Physical Quantity
Expression
Unit
1
Area
length×breadth
m2
2
Volume
area×height
m3
3
Density
massvolume
kgm3
4
Velocity
displacementtime
ms1
5
Momentum
mass×velocity
kgms1
6
Acceleration
velocitytime
ms2
7
Force
mass×acceleration
kgms2orN
8
Pressure
forcearea
Nm2orPa
9
Energy (Work)
force×distance
NmorJ
10
Surface tension
forcelength
Nm1