Question

A uniform wooden plank of mass 30 kg is kept on
two supports X and Y as shown. The length of the
plank is L. Reaction force applied by Y as shown is
(g = 10 m/s2)

Answer 1

(The figure missing in the question is attached below)

Given:

Mass of wooden plank = 30 Kg

To find:

The Reaction force applied at point Y

Calculation:

As the wooden plank is uniform,the mass of the plank will act at the center of mass of the plank

By taking moments of force at point X

 $\Rightarrow300\times \frac{L}{2} -[R_{Y}\times (\frac{3L}{4})]=0$

     $300\times \frac{L}{2} =R_{Y}\times (\frac{3L}{4})$

     $150=R_{Y}\times\frac{3}{4}$

     $R_{Y}=200N$

Final answer:

The Reaction force applied at point Y is 200 N