Question

Which of the following is/are equations of uniformly accelerated motion relating the initial velocity (u), final velocity (v), time (t), acceleration (a) and displacement (S).

• A. $v^2=u^2+2aS$
• B. $v=u+at$
• C. $S=ut+\frac{1}{2}a{t}^2$
• D. All the above

Answer 1

Answer: (D)

All the above

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:

• $v=u+at$
• $s=ut+\frac{1}{2}a{t}^2$
• $v^2{=u}^2+2as$

The equations of motion can only be used for an object travelling in a straight line with a constant acceleration.