Determine the coefficient of friction between a ball bearing and a roller coaster if the roller coaster starts with an 12.02 g ball being dropped from a height of 1.55 m (ignore friction during drop), and finishes the 6.15 m track along the floor with a speed of 4.2 m/s.

Julia would be observing a. static electricity was caused by her sweater rubbing against her shirt and transferring electrons. she didn't touch anything metal, so that would cancel out b.she most likely didn't rub her sweater against her hair either, so that cancels out c.she also didn't scoot across the carpet while trying to take her sweater off, that cancels out d.so that leaves a.a. is correct.

It's because 3 if it was 10 it wouldn't look right do it goes up to 4d

Is this a question of an answer