Section 3.7 2. (12 pts) Lets(t) =It*-213-212+ 24t give the position of an object, in meters, on a coordinate line at time t seconds, t 2 0. (a) When is the object moving forward? Standing still? (Hint: 13 -612 -4t + 24 = (12 -4)(t-6)) (b) When is the object slowing down?Position Suppose that an object is moving along a coordinate line, so that we know its position y on the line as a function of time . We call at the positron function . (xitl) What does the sign of the position function tell us! 4 = 64) Ex Lei Sit)= 40-t Sign of aft Interpretation the rocket is be the position above ground 40 in feet of the rocket is a rocket al below ground + + seconds 140 the racket is at t20 ground level(sIt) ) = c'it) Velority tell us how fast an object is moving, as well as, the direction of the movement. What does the sign of the velocity function tell us" Sign of vit) Interpretation object is moving forward (or to the right) object is moving t backward (or to the left) object is stopped Speed is defined asWhat does the sign of the acceleration function tell us! Sign of sit) Interpretation the velocity is 7 slope of the tangent increasing lines are positive (to velocity funthon ) the velocity 15 slope of the tangent lines decreasing to the velocity function are neganve object has stopped accelerating itj = altj = v"it] -s"(+)at (speed) S Alt) V() >0 - att ) vit] co Speeding up ( speed ) 76 if vit) >0 and alt170 If vit) and alt) have the vit]co and (alt) 70, alt) 0 i's increasing SLOWING DOWN if (alt]co vit]co * alt)70 If vit ) and atty have 82070 kelli Karkarthen opposite sign! the speed is thecreasing