Question

It you balance a weight of 20 N at the 15 cm MARK and want to balance a weight of on the other side of the meter stick at 70 cm MARK, what weight should you place there

Answer 1

Answer:

The weight that will balance the meter stick at 70 cm mark is 35N

Explanation:

Given;

first weight at 15 cm mark, W₁ = 20 N

second weight at 70 cm mark, W₂ = ?

A sketch of the question in diagram form;

The center of gravity of the meter stick is 50 cm

                     15cm               50cm         70cm

0---------------------------------------Δ------------------------------------------100cm

                     ↓                                           ↓

                     20N                                      W₂

                     <------------------>|<--------------->

                                35cm               20cm

Take moment about the pivot;

Clockwise moment = anticlockwise moment

W₂(20cm) = 20N(35 cm)

W₂ = (20 x 35) / (20)

W₂ = 35 N

Therefore, the weight that will balance the meter stick at 70 cm mark is 35N