Determine the mass of the wooden block, to at least 1 decimal place. (Give the info below)

Question

The amount a string stretches varies linearly with the mass applied to the spring, as can be seen in the video. In the video, with no additional mass, the hanger was 30.6 cm off the ground. With 150 grams of additional mass, the hanger was 16.2 cm off the ground.

A wooden block stretched the spring so the hanger was 21.2 cm off the ground. Determine the mass of the wooden block, to at least 1 decimal place.

Answer 1

Answer 2

We can set this up as a ratio proportion problem:

( 30.6 - 16.2 ) / 150 = ( 30.6 - 21.2 ) / x

14.4 / 150 = 9.4 / x

x = 9.4 * 150 / 14.4 = 97.92, rounded to 2 decimal places, or 97.9 grams, rounded to 1 decimal place.

Aa a quick check, note that the displacement with 150 grams is about 15 cm. Thus, when the displacement is approximately 10 cm, we would expect a 100 gram mass.