A cable with a diameter of 6mm is used to lift crate. Calculate the mass of the crate required to create a stress of 350 MPa.

Let's begin with the definition of stress:

Stress = F/A

First, we need to recall that the force the weight of the crate will exert on the cable will be equal to:

F= m*g

We know the stress, g and A. Combining this we can write:

Stress = m*g/A

Rearrange for the mass:

A*Stress/g = m

We can calculate the cross-sectional area of the cable using the equation for the area of a circle:

Area = pi*r²

Remember to half the diameter and convert it into meters before calculating the area!

Area = pi*(0.006/2)² = 2.827 * 10^-5 m²

Now we sub everything in:

m = (2.827 * 10^-5)(35010⁶)/9.81 

m = 1008.6kg