a student wants to determine the coefficient of static friction and kinetic friction between a box and a plank by gradually raising one end of the plank. when the angle of inclination with the horizontal reaches 28.0, the box starts to slip and slide 2.53 m down the plank in 3.92 s. find the coefficients of friction
1 answer
Cofficient of static friction=tan28=0.53 (b)mgsin28-ukmgcos28=ma cancel m d=1/2at^2 2.58=1/2a(3.92)^2 a=0.336m/s^2 substitute a:4.695-8.829uk=0.336 8.829uk=4.359 uk=0.49