Physics: Calculate the Acceleration of a Sled Heading Down a Hill
Problem: Calculate the acceleration of a sled that is heading down a 40° slope (one that makes an angle of 40° with the horizontal). The coefficient of kinetic friction on ice is μk = 0.100.
First start by drawing a force diagram with positive X down the hill, parallel to the incline, and Y perpendicular to the surface.
Use the formulas Fk = force of kinetic friction = μk * n and Fnet = ma
Positive X: MGsin(40), Negative X: μk * n
Positive Y: N, Negative Y: MGcos(40)
Now set Fnet = positive X – negative X
Fnet = MGsin(40) – μk * n
Substituting MA for Fnet, we get:
Gsin(40) – μk * Gcos(40) = A = 5.55 m/s^2
Answer: A = 5.55 m/s^2