Question: The record for grass skiing was set blah blah blah. Suppose it took Spinka 6.60 s to reach his top speed after he started from rest down a slope with a 34 degree incline. If the coefficient of friction between the skis and the grass was 0.198, what was the magnitude of Spinka's net acceleration? What was his speed after 6.60 s? Here's what I've done: I thought a=g(sinTheta) Which gives me a = 9.81(sin34) a = 5.486 m/s2, which isn't right. What am I doing wrong?