#### Problem 1E

1. The displacement (in meters) of an object moving in a straight line is given by $s=1+2 t+\frac{1}{4} t^{2}$, where $t$ is measured in seconds.

(a) Find the average velocity over each time period.

(i) $[1,3]$

(ii) $[1,2]$

(iii) $[1,1.5]$

(iv) $[1,1.1]$

(b) Find the instantaneous velocity when $t=1$.