1. The displacement (in meters) of a particle moving in a straight line is given by s = t² 5t + 15, where t is measured in seconds.(a) Find the average velocity over each time interval.

(i) [3, 4] ____________ m/s (ii) [3.5, 4] ______________ m/s (iii) [4, 5] ______________ m/s (iv) [4, 4.5] _____________ m/s (b) Find the instantaneous velocity when t = 4. ____________ m/s

2.