# Math Help - physics help

1. ## physics help

person stands a distance of 0.300 meters from the right end of a 2.00 meter long uniform platform that is supported by two posts, one at each end. The board has a mass of 20.0 kg and the person's mass is 75.0 kg.

a. determine the force exterted on the board by the post on the left end.

b. determine the force exerted on the board by the post on the right end.

Thank you

2. static equilibrium ...

$\sum F_y = 0$

let $F_L$ = upward force of the support on the left end
$F_R$ = upward force of the support on the right end

$F_L + F_R = 20g + 75g$

$\sum \tau = 0$

let the left end be the pivot point ...

$\tau_{cw} = \tau_{ccw}$

$20g(1.0) + 75g(1.7) = F_R(2.0)$

solve for $F_R$ and $F_L$