Last time we introduced the frictional force formula which is used to calculate the engineering expert must sometimes negotiate. Today we’ll plug numbers into that formula to calculate the present in our example scenario involving broken ceramic bits sliding across a concrete floor.frictional force Here again is the formula to calculate the
× m × gwhere the frictional force is denoted as m, and g is the gravitational acceleration constant, which is present due to Earth’s gravity. The Greek letter μ, pronounced “mew,” represents the coefficient of friction, a numerical value predetermined by laboratory testing which represents the amount of at play between two surfaces making contact, in our case ceramic and concrete.friction To calculate the m of a given ceramic piece is 0.09 kilograms, μ is 0.4, and the gravitational acceleration constant, g, is as always equal to 9.8 meters per second squared.
Using these numerical values we calculate the
× m × g
× (0.09 kilograms) × (9.8 meters/sec)^{2}
kilogram meters/sec^{2}
Newtons The of 0.35 Newtons amounts to 0.08 pounds of frictional force which is approximately equivalent to the combined stationary weight force of eight US quarters resting on a scale.force, Next time we’ll combine the frictional force formula with the Work-Energy Theorem formula to calculate how much kinetic energy is contained within a single piece of ceramic skidding across a concrete floor before it’s brought to a stop by Copyright 2016 – Philip J. O’Keefe, PE Engineering Expert Witness Blog ____________________________________ |