Question

The three equations of motion how we can understand that where we have to use the three equations of motion to solve the questions and how we can understand that there we have to use 1eq,2 eq or 3eq?

Answer 1

Equations of motion

The equations of motion relate to the following five quantities:

• u - initial velocity
• v - final velocity
• a - acceleration
• t - time
• s - displacement

Of the above u, v, a, and s are vector quantities. As such, remember to make vectors going in one direction positive and vectors in the opposite direction negative.

Time (t) is a scalar quantity.

If any three of the five quantities are known then the other two may be calculated using the following three equations:

1. v = u + at
2. s = ut + ½at²
3. v²= u²+ 2as

we use these equations to find the unknown in a given question.

for example :- In a question u,a and t is given then we use the first equation in which only v unknown.like wise we use the equations as asked in the questions given