A 63 kg hiker is dangling over the edge of an icy cliff. His partner (80 kg) is standing on icy ground holding a rope to keep the dangling hiker from falling. What coefficient of friction is needed to keep them from sliding?
- JenkinLv 74 月前最愛解答
Assume non-elastic force transfers,
63kg hiker hanging in air of the cliff = 63 x 9.81 = 618.03N
To hold this pulling force, the partner standing on "ice" ground require a weight force resistance on the ground without sliding (no moving):
Pulling Force P = Friction Force = u W = coefficient of friction (of ice surface against the foot of the person) x weight of the person.
618.03 = u (80kgx9.81)
u = 0.7875