What is physical quantity ? Write its types.
To describe natural and man made events around us many concepts are required. These concepts are called quantity.
There are two types of unit.
$(1)$ Fundamental quantity: Minimum number of quantities which are independent of each other and by using these quantities any event can be described are called fundamental quantities.
Eg. : length, mass and time.
$(2)$ Derived quantity : Quantity which are obtained by using fundamental quantity are called derived quantity.
E.g. : velocity, acceleration, force, work, power.
The velocity of a particle depends upon the time $t$ according to the equation $v = \sqrt {ab} + bt + \frac{c}{{d + t}}$ The physical quantities which are represented by $a, b, c$ and $d$, are in the following order
In $S = a + bt + c{t^2}$. $S$ is measured in metres and $t$ in seconds. The unit of $c$ is
Unit of Stefan's constant is
The unit of angular acceleration in the SI system is
Unit of energy is