Hi again.. I know this can't be that difficult but I am faced with a terrible book and a professor that spends no more than 10 minutes on each chapter. So, here goes.. Again, not looking for an answer, just some ideas on where to start...

 

A 70-kg tightrope walker stands at the midpoint of a 100 m rope. The rope sags 1.5 m. What is it's tension.

 

I know I have to use w=ma to find the weight, and I've tried finding the angle between the 2 segments of rope, but I keep getting goofed up somewhere. Thanks in advance!

If the walker in the in the middle, the sagging of the rope will make it form a triangle correct? The property of rope is that it can only support forces along its axis, that is it cannot exert torques. Resolve the horizontal and vertical directions. The two vertical forces must be equal to the weight of the walker. That's the key to solving this problem.

 

Why don't you work out the problem and we'll see how we can assist you from there.

Starting point for any classical mechanics problem: Draw a "free body diagram".

 

Use component vectors to show tension in the rope and its horizontal and vertical component forces, along with the angle made by the rope with respect to the horizontal plane.