Answer to Question #207426 in Classical Mechanics for ToesAreNice

Question

Your materials are a plank of wood, a ruler, protractor, and photo gate. Describe an experiment below

for determining the coefficient of kinetic friction between the plank of wood and the tissue box. Assume that you are on Earth

and the downwards direction is negative and the upwards direction is positive and that the mass of the tissue box is 143.7 grams.

Answer 1

The experiment:

1) take a plank of wood

2) put the box on the plank

3) put the protractor so you may measure the angle between the plank and horizontal

4) start the photogate

5) start increasing the angle above the horizontal of the plank until the box slides at constant speed

6) record this angle $\theta$

7) the coefficient of kinetic friction is

$$\mu_k=\tan\theta$$