36 6 The position of a body moving on a coordinate line is given by s = t2 ? for 1 g t g 6, With s in meters and t in seconds. (3) Find the body's displacement and average velocity for the given time interval. Displacement = 111 Average velocity = m/s (b) Find the body's velocity at the endpoints of the interval. Velocity at t = 1 is m/s Velocity at t = 6 is m/s (c) Find the body's acceleration at the endpoints of the interval. 2 Acceleration at t = 1 is m/s 2 Acceleration at t = 6 is m/s (d) When, if ever, during the interval does the body change direction? If there is more than one answer, enter a comma separated list. If the body never changes direction during the interval, enter NONE. t=s (1 point) If R denotes the reaction of the body to some stimulus of strength as, the sensitivity S is dened to be the rate of change of the reaction With respect to w. A particular example is that when the brightness at of a light source is increased, the eye reacts by 40 24x04 1 4500-4 on a; when R is measured in sq m and a: is measured in the appropriate units of brightness. has been used to model the dependence of R decreasing the area R of the pupil The experimental formula R(ar;) = Find the sensitivity. R' (3:) =