Question

A lift of mass 2000kg is supported by thick steel ropes. if the maximum upward acceleration of the lift be 1.2m/s and the breaking stress fir the rope be 2.8​

Answer 1

Answer:

The diameter of the rope will be 1 cm

Explanation:

According to the problem the , m = 2000 kg

let the tension of the rope is T

Now the maximum acceleration of the lift is, a=  1.2m/s^2

Now Newton's 2nd law we can say that net force = ma

Therefore,

T - mg = ma

T = m(g+a)

T= 2000 x (9.8 + 1.2)

  = 2000 x 11 N

Now stress is = 2.8 x 10^8 N/ m^2

Stress= Force/ Area = Force/ πd^2/4

    Here force is Tension

Therefore,

Stress = 4T/πd^2 [ where d is the diameter]

Therefore,

4T/πd^2 = 2.8 x 10^8

=> 4 x 2000 x 11 / 3.14 x d ^2 = 2.8 x 10^8

by calculating this

we will get

d = 10^(-2) m or 1 cm

Answer 2

Answer:

see the attachment

Hope

this helps you ...