Question

1. An old rope can only safely suspend 120 kg. The old rope losses 20 kg of holding strength per minute once it's under tension from any thing over 80 kg. When the rope is tied to a beam, it hangs down with a vertical length of 12.0 m.

a. Calculate the minimum time required for a 85 kg person starting from rest to climb the entire length of the rope without breaking it.
b. What would the minimum vertical velocity of the climber be to reach the top safely?

Answer 1

a. 1.75 min

b. 6.86 m/min

Step-by-step explanation:

The difference between the rating and the person's weight is:

120 kg − 85 kg = 35 kg

The time to lower the rating that much is:

35 kg / (20 kg/min) = 1.75 min

The minimum velocity of the climber is:

12.0 m / 1.75 m = 6.86 m/min