14. copernicus's model of the universe differs from ptolemy's because copernicus believed
a. the sun and earth share a central point from which the other planets rotate around them.
b. earth rotates on its axis and orbits the sun.
c. earth orbits the sun but remains stationary on its axis.
d. earth is still at the center but rotates on its axis.

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =

Which sound characteristic is not affected by the relative motion of an object

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?