weight bearing force

Question

two match officials carry an injured rugby player from a rugby field on a stretcher. The rugby player weighs 95 kg and the stretcher is 2.5 m long. One of the stretcher bearers (bearer A) is able to lift a weight of 60 kg; the other bearer (bearer B) is unsure how much weight he is able to lift.

a) How much weight must bearer B support?

b) How far from bearer A must the injured rugby players center of mass be in order for the stretcher bearers to carry the load without tipping the injured player out?

Answer 1

First, let's draw a picture of this.

a) A total of 95 kg must be born so Bearer B must be carrying 35 kg. (x = 35 in this picture)

b) To not tip, 60 x d₁ must equal 35 x d₂ but d₂ = 2.5 - d₁ so 60d₁ = 35(2.5 - d₁)

60d₁ = 35(2.5 - d₁)

60d₁ = 87.5 - 35d₁

95d₁ = 87.5

d₁ = 87.5/95 = 0.92m

That leaves Bearer B's side to be 2.5 - 0.92 = 1.58 m