Question

Find the unknown mass of the block 1 needed to balance the bar. Assume that the mass of the bar is negligible. Block 1 is located 0.85 m left of the center of the bar. Blocks 2 and 3 are located at 0.25 m and 0.50 m right of the center of the bar. The masses of the blocks 2 and 3 are showed. Give the result in the nearest whole number. Do not include units in the result. Use the gravity acceleration on Earth, g = 10 m/s2

Answer 1

Incomplete question: The masses of the blocks m₂ = 1.5 kg and m₃ = 2 kg

Step-by-step explanation:

Given data:

L₁ = length = 0.85 m

L₂ = 0.25 m

L₃ = 0.5 m

m₂ = 1.5 kg

m₃ = 2 kg

Question: Find the unknown mass of the block 1 needed to balance the bar, m₁ = ?

The torque is zero (intermediate point of the bar)

`-m_(1) gL_(1) +m_(2) gL_(2) +m_(3) gL_(3) =0`

Is negative because mass 1 is to the left of the coordinate system (see the diagram)

`m_(1) =(m_(2) gL_(2)+m_(3) gL_(3) )/(L_(1) ) =((1.5*0.25)+(2*0.5))/(0.85) =1.6176kg`