Positive and negative charges are attracted to one another. the phenomenon of static electricity requires a separation of positive and negative charges. laundry in a clothes dryer often becomes charged with static electricity while drying. which of these best explains why a clothes dryer often generates static electricity? a) short circuits in the dryer charge the laundry. b) heat from the dryer charges the air and produces lightning. c) clothes with metal pieces conduct electricity in the dryer. d) electrons are transferred as clothes rub against each other in the dryer.

The base of a 50-meter tower is at the origin; the base of a 50-meter tree is at (0, 50, 0). the ground is flat and the z-axis points upward. the following parametric equations describe the motion of six projectiles each launched at time t = 0 in seconds. (i) r (t) = (50 + t2)k (ii) r (t) = 2t2 j + 2t2k (iii) r (t) = 50 i + 50 j + (50 − t2)k (iv) r (t) = 2t j + (50 − t2)k (v) r (t) = (50 − 2t) i + 2t j + (50 − t)k (vi) r (t) = t i + t j + tk (a) which projectile is launched from the top of the tower and goes downward? at time t = , the projectile hits the ground at point (x, y, z) = . (b) which projectile hits the top of the tree?