A movie stunt woman takes a running jump from the roof of one building to that of a lower building.She leaves the taller building traveling perfectly horizontally at 6.1 m/s and just makes it to the edge of the roof of the lower building.The horizontal gap between the buildings is 2.8 m.The difference in height between the two buildings is
A)1.0 m.
B)1.4 m.
C)2.3 m.
D)2.8 m.
E)3.0 m.

Question

Quizplus · Accepted Answer

The stunt woman's horizontal velocity is constant, so her horizontal displacement is:$$d = vt = (6.1 \ m/s)(t)$$Her vertical displacement is:$$y = -1/2gt^2 = -(1/2)(9.8 \ m/s^2)t^2$$When she reaches the edge of the lower building, her horizontal displacement is equal to the gap between the buildings:$$d = 2.8 \ m$$So:$$(6.1 \ m/s)(t) = 2.8 \ m$$$$t = 0.46 \ s$$Her vertical displacement is then:$$y = -(1/2)(9.8 \ m/s^2)(0.46 \ s)^2 = -1.0 \ m$$So the difference in height between the two buildings is 1.0 m.

A Movie Stunt Woman Takes a Running Jump from the Roof