59. A block resting at the top of a plane inclined at 26° with the horizontal slides down with an acceleration
of 1.96 m/s^2 [down the plane). Calculate the coefficient of
kinetic friction.

μ = 0.265

Explanation:

F = ma

mgsinθ - μmgcosθ = ma

gsinθ - μgcosθ = a

gsinθ - a = μgcosθ

μ = (gsinθ - a) / gcosθ

μ = (9.81sin26 - 1.96) / 9.81cos26

μ = 0.265439...

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

hope this ! : )