Question

Suppose we take a 1 m long uniform bar and support it at the 33 cm mark. Hanging a 0.15 kg mass on the short end of the beam results in the system being in balance. Find the mass of the beam.

Answer 1

Answer:

The mass of the beam is 0.074 kg

Explanation:

Given;

length of the uniform bar, = 1m = 100 cm

Set up this system with the given mass and support;

  0-----------------33cm-----------------------------------100cm

  ↓                     Δ                                             ↓      

0.15kg                                                              m

Where;

m is mass of the uniform bar

Apply the principle of moment to determine the value of "m"

sum of anticlockwise moment = sum of clockwise moment

 0.15kg(33 - 0) = m(100 - 33)

0.15(33) = m(67)

$m = \frac{0.15kg(33 \ cm)}{67 \ cm}\\\\m = 0.074 \ kg$

Therefore, the mass of the beam is 0.074 kg