A 75 k g climber finds himself dangling over the edge of an ice cliff, as shown
ID: 2137856 • Letter: A
Question
A 75kg climber finds himself dangling over the edge of an ice cliff, as shown in the figure below. Fortunately, he's roped to a 840kg rock located 51m from the edge of the cliff. Assume that the coefficient of kinetic friction between rock and ice is 5.7
A 75kg climber finds himself dangling over the edge of an ice cliff, as shown in the figure below. Fortunately, he's roped to a 840kg rock located 51m from the edge of the cliff. Assume that the coefficient of kinetic friction between rock and ice is 5.7 times 10?2. What is his acceleration, and how much time does he have before the rock goes over the edge? Neglect the rope's mass.Explanation / Answer
kinetic friction = u.mg = 5.7 x 10-2 x 840 x 9.8 = 469.22 N
75g - T = 75a
T - 469.22 = 840a
add them
a = 0.290 m/s2
using h =ut + at^2/2
51 = 0 + 0.290 x t^2 /2
t = 18.55 sec