Question

A 56 kg woman climbs the stairs to a height of 5 m. Determine: a) what mechanical work

she performed; b) what work the woman will do when climbing the stairs and carrying a 5 kg load.

Answer 1

a) W = 2746.8[J]

b) W = 2992.05 [J]

Step-by-step explanation:

Work is defined as the product of force by distance. We must bear in mind that the force that performs the work is the one that acts in the same direction of displacement.

For this case, we must calculate the weight of the woman, the weight is defined as the product of mass by gravity.

`w=m*g\\`

where:

w = weight [N] (units of Newtons]

m = mass = 56 [kg]

g = gravity acceleration = 9.81 [m/s²]

`w=56*9.81\\w=549.36[N]`

a)

`W=F*d`

where:

F = weight = 549.36[N]

d = distance = 5 [m]

`W = 549.36*5\\W = 2746.8[J]`

b)

The new mass will be the combination of the mass of the woman plus that of the load.

`m_(new) = 56+5\\m_(new)=61[kg]`

`w_(new)=61*9.81\\w_(new)=598.41[N]`

The new work done.

`W =598.41*5\\W=2992.05[J]`