Question

A rigid plank 5.00 m long has mass 30.0 kg and supports a 75.0 kg block 2.00 m from the left end. How much force is needed to support each end of the plank?

Answer 1

$$mg*2+Mg*2.5=R_B*5$$ $$R_B=441\:\rm N$$ $$R_A=mg+Mg-R_B=588\:\rm N$$