I am having a bit of trouble with this one.

A safety harness is connected to a cable with a report breaking stress of 800MNm-2. What mass could be hung from a harness if the diameter of the cable was 6mm?

To determine the mass that could be hung from the harness, we need to calculate the maximum allowable tension in the cable based on the given breaking stress.

The formula to calculate tension in a cable is:

Tension = Stress × Area

First, we need to find the area of the cable. The formula to calculate the area of a circle is:

Area = π × (radius)²

Given that the diameter of the cable is 6mm, we can calculate the radius by dividing the diameter by 2:

Radius = Diameter / 2 = 6mm / 2 = 3mm

Next, we need to convert the radius from millimeters to meters, as the stress in MN/m² is given:

Radius = 3mm / 1000 = 0.003m

Now we can calculate the area:

Area = π × (0.003m)²

To calculate the maximum allowable tension, we need to multiply the area by the breaking stress:

Tension = Stress × Area

Substituting the given breaking stress value of 800MN/m²:

Tension = 800MN/m² × Area

Finally, we can solve for the mass. To find the mass, we need to use the equation:

Force = Mass × Acceleration

In this case, the force is equal to the tension in the cable, and the acceleration is the acceleration due to gravity, which is approximately 9.8 m/s². Rearranging the equation, we get:

Mass = Force / Acceleration

Substituting the tension we calculated earlier for the force, we have:

Mass = Tension / Acceleration

Substituting the calculated tension and the gravitational acceleration into the equation, we can now solve for the mass that could be hung from the harness.