Recent content by riggi91

Homework Statement A 4-kg rock is tied to the end of a string and twirled overhead, 1.6 m above the ground, in a 1.1-m radius, horizontal circle. The string is known to break if its tension reaches a value of 514 N. The rock it rotated faster and faster until the string breaks. How far...

I got the answer. after i found vf i used a=v/t and then just used F=ma and my answer was 879727.5N Thank you for your help!

Duh! I don't know why I didnt realize that before. I also believe I've found vf I used vf^2=vi^2-2ad and got 39.099 m/s for the vf. If that is correct would i just use a=v/t to find out a?

Homework Statement Superman (m = 90 kg) jumps over a 78 m tall building by first accelerating from rest to his maximum velocity in 0.004 s. Subsequent to this time, Superman follows normal projectile motion. What is the average force acting on Superman that gives his upward acceleration...