Question

You are a thief and you want to lower yourself from the rooftop to a second floor window, which is at a distance H=12m below the tip of the roof. You want to use a nylon rope, which has a failure stress of 400 MPa, and a Young’s modulus of 1 GPa. If you weigh 225 lb, what diameter rope, Dmin, should you choose if you want a safety factor of 2 against failure?

Answer 1

2.4
10

Answer 2

Thanks Sat, but can you write your reasoning behind the answer?

Answer 3

Rotating blade (body force in axial loading)

A blade is fixed to a rigid rotor of radius R spinning at omega rad/sec around the vertical z-axis (see figure). Neglect the effects of gravity.

Calculate the peak stress in the blade: sigma_max_n
Calculate the blade elongation: delta
Calculate the displacement of the blade mid-section: u_x(L/2)

sigma max n =
delta =
u_x(L/2) =

Answer 4

please help me what is the solution of above questions.?

Answer 5

please help me if anybody find the solution of above question.

Answer 6

Has somebody figured out?

Answer 7

Anybody for Problem 1 and 2?

Answer 8

Problem 1 and 2?

Answer 9

help me plz

Answer 10

Problem 1 and 2 please?

Answer 11

rho*omega^2*(R*L+L^2/2)
(rho*omega^2/E)*(L^3/3+L^2*R/2)
(rho*omega^2/E)*(11*L^3/48+3*L^2*R/8)

Answer 12

Thanks gluglu, anyone for last problem in question 1?

Answer 13

Anyone for last question in Problem 1 please?