Q. A 61.0-kg speed skater with a velocity of 17.0 m/s comes into a curve of 15.0-m radius. How much friction must be exerted between the skates and ice to negotiate the curve?
Q. A 247- projectile, fired with a speed of 143 at a 69.0 angle, breaks into three pieces of equal mass at the highest point of its arc (where its velocity is horizontal). Two of the fragments move with the same speed right after the explosion as the entire projectile had just before the explosion; one of these moves vertically downward and the other horizontally.