Answer to Question #7003 in Mechanics | Relativity for adoo
a taxi driver allows his taxi cab weighing 17.08 kN to coast in neutral, and air resistance decelerates the car from 35.8 m/s to 22.4 m/s in a period of 24 seconds. calculate (a) the average deceleration, (b) the displacement of the car while it is decelerating.
(a) the average deceleration
Let a be the average deceleration. Then V(t) = at + V0. We know that V(T) = V1, so aT + V0 = V1, or 24a + 35.8 = 22.4 ==> a = (22.4-35.8)/24 = -67/120 m/s².
(b) the displacement of the car while it is decelerating.
We'll use the formula D(t) = at²/2 + V0*t. So, D(T) = aT²/2 + V0*T = -67/120*24²/2 + 35.8*24 = 3492/5 m.