Panic escape . The figure below shows a general situationin which a stream of pe
ID: 1664351 • Letter: P
Question
Panic escape. The figure below shows a general situationin which a stream of people attempt to escape through an exit doorthat turns to be locked. The people move toward the door at speedvs = 3.8 m/s,are each d = 0.20 m in depth, andare separated by L = 1.75 m. The arrangement in the figureoccuurs at time t = 0. (a) At what average rate the layer of people atthe door increase?1 m/s
(b) At what time does the layer's depth reach 5.4 m? (The answer reveals how quickly such asituation becomes dangerous.)
2 s (a) At what average rate the layer of people atthe door increase?
1 m/s
(b) At what time does the layer's depth reach 5.4 m? (The answer reveals how quickly such asituation becomes dangerous.)
2 s
Explanation / Answer
People's speed vs = 3.8m/s depth d = 0.20m Speration between them L = 1.75m Initial time = 0sThe amount of time it takes one person to move a distance L withspeed vs is t = L/vs
A)The rate of increase of people is
R = d/t = d/(L/vs) = dvs/L = (0.20m) (3.8 m/s) / ( 1.75 m) = 0.43 m/s
B) The amount of time is given by D = 5.4 m
t = D/R = ------ s Solve it People's speed vs = 3.8m/s depth d = 0.20m Speration between them L = 1.75m Initial time = 0s
The amount of time it takes one person to move a distance L withspeed vs is t = L/vs
A)The rate of increase of people is
R = d/t = d/(L/vs) = dvs/L = (0.20m) (3.8 m/s) / ( 1.75 m) = 0.43 m/s
B) The amount of time is given by D = 5.4 m
t = D/R = ------ s Solve it
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.