Chad is tied to one end of a 40-m elasticized (bungee) cord. The other end of the cord is tied to the middle of a bridge. If Chad jumps off the bridge, for how long will he fall before the cord begins to stretch? (Use 4.9t2 = s.)

Question

anonymous · Answer

equation of motion: y = 0.5 a t^2 + Vot + yo

y = 0.5 a t^2 + Vot + yo   with yo=0, Vo =0, y = -40 and a = -10

-40 = 0.5 (-10) (t^2) + 0t + 0 

-40 = 0.5 (-10) (t^2)

4 = 0.5 (t^2) 

8 = t^2

t = sqrt(8) 

SIMPLIFIED ANSWER: 2sqrt(2)