A 3-column table with 4 rows. The first column titled substances has entries aluminum, zinc, chromium, nickel. The second column titled density has entries 2.70 grams per centimeter cubed, 7.13 grams per centimeter cubed, 7.18 grams per centimeter cubed, 8.90 grams per centimeter cubed. The third column titled mass has entries 4.60 grams, 9.81 grams, 6.24 grams, 3.17 grams. Use the information in the table to identify the metal with a volume of 1.38 cm3.

aluminum
zinc
chromium
nickel

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?