Question

Starting at t=0, an object moves along a straight line with velocity in m/s given by v (t)= 98-2+2, where t is in seconds, What Acceleration in m/s? when the object momentarily stops?

Answer 1

The object will stop when $v=0$ . So, we have

$98-2t^2=0\to t=7\ (s)$

$a=\frac{dv}{dt}=-4t$ . For $t=7\ (s)$ $a=-4\cdot7=-28\ (m/s^2)$ . Answer