Superman is standing 124 m horizontally away from lois lane. A villian drops a rock vertically downward with a speed of 2.26 m/s from 19.3 m directly above Lois.
a) If Superman is to intervene and catch the rock right before it hits Lois, what should be his minimum constant acceleration?
b) How fast will Superman be traveling when he reaches Louis?
a) time taken by rock :
using d = ut + gt^2 /2
19.3 = 2.26t + 4.9t^2
t = 1.77 sec
superman have to travel 124m in 1.77 sec
so , 124 = 0 + a x 1.77^2 /2
a =79.16 m/s2
2) v = u + at = 79.16 x 1.77 = 140.11 m/s