Question

A particle moves in a straight line, its position (in m) as function of time is given by `x = (at^2 + b)`.
What is average velocity in time interval `t = 3 sec` to `t = 5 sec` ? (Where `a` and `b` are constant and `a = 1 m//s^2, b = 1 m`.)
A. `8 m//s`
B. `5 m//s`
C. `10 m//s`
D. `12 m//s`

Answer 1

Correct Answer - A
`V_(avg) = (x_f - x_i)/(t_f - t_i)`
=`((1 xx 5^2 + 1)-(1 xx 3^2 + 1))/(5 - 3) = (16)/(2) = 8 ms^-1`.