Why is momentum represented by p?
In physics there is a quantity that represents the product of mass and velocity of an object. That quantity is called as momentum. The popular equation for momentum according to the Newton’s law is that P=MV. Here, P stands for momentum, M stands for mass and V stands for Velocity of an object. If we observe the symbols used for various other quantities in physics, mass, time, velocity, force, acceleration are represented by their first letters. In this context, we might think that probably momentum is represented by Ã¢â‚¬ËœP’ as Ã¢â‚¬Ëœm’ was already used for mass. If Ã¢â‚¬Ëœm’ was not used for mass, probably it could have been used for momentum. These usages existed since few decades.
Before the Newton’s period it was believed that an object moves when a force is applied on it continuously. Later, Newton discovered Ã¢â‚¬Ëœmomentum’ which showed that object moves continuously without any force applied on it. The capacity or characteristic feature of the object to move continuously was called as impetus. Though Newton talked about momentum, he did not formulate the equation P=MV. This equation was formulated after some time. This study was later called as Newtonian mechanics. In the place of previous Ã¢â‚¬Ëœimpetus’, the name momentum was used by the people. Probably, Ã¢â‚¬ËœP’ was convenient symbol as per its previous name and that might have led to the representation of momentum with Ã¢â‚¬ËœP’. The letter is written in bold as the quantity is a vector.
Some interpret the reason for keeping PÃ¢â‚¬Â as symbol for momentum as the letter being derived from Latin word PetereÃ¢â‚¬Â which means to go and seekÃ¢â‚¬Â. This meaning is also related to the word Ã¢â‚¬Ëœimpetus’ which is the earlier term used for Ã¢â‚¬Ëœmomentum’. The word Ã¢â‚¬Ëœimpetus’ gives the meaning as to go and rush uponÃ¢â‚¬Â which was explained by the term PetereÃ¢â‚¬Â. Hence, momentum is represented by the letter PÃ¢â‚¬Â.