There is a good deal of stored energy in gasoline, which makes it useful as fuel for cars. When gasoline is burned in a car engine, what happens to this energy? A. It is destroyed as it is used to make the engine in the car run.
B. Some of it is transformed into kinetic energy and some into potential energy.
C. Some of it makes the car run, but most of it disappears before being transformed.
D. It is transformed into kinetic energy, sound energy, and heat energy.

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?