posted by Anonymous .
A uniform rod (AB) of mass 80kg and 1.0m lenght is supported on the 2 knife edges placed 15.0cm from its ends. what will be the reactions at these support when a 20kg mass is suspend 10cm from the mid-point of the rod.(workings and diagram)
sum vertical forces. Let fl be the knife edge left support, and fr be the right support.
fl+fr=80+20 in kg
sum moments about the left knife edge.
solve for the force right. then in the other equation lf.
Now in newtons, multiply by 9.8, kg is not a force.