Question

A basic wall mounted shelf is designed from a wooden board of uniform mass of 50 kg and is 30 cm long (from the wall).  The shelf in being supported by a bracket connected to the wall and 2 dowel rods pushing from the bottom, making an angle of 60° to the wall and contacts the shelf 20 cm from the wall, as shown in the diagram below. Each dowel rod has a diameter of 1 cm and a maximum compressive strength of 5 x 10⁶ N/m².

Calculate the maximum compressive force that can be exerted by a single dowel rod.

Calculate the maximum amount of weight, in newtons, that can be placed at the edge of the shelf.

Calculate the horizontal component of the force acting on the bracket attached to the wall.

Calculate the vertical component of the force acting on the bracket attached to the wall.

Answer 1