The base of a 40-meter tower is at the origin; the base of a 40-meter tree is at (0, 40, 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) = (40 + t2)k
(II) r (t) = 2t2 j + 2t2k
(III) r (t) = 40 i + 40 j + (40 â t2)k
(IV) r (t) = 2t j + (40 â t2)k
(V) r (t) = (40 â 2t) i + 2t j + (40 â t)k
(VI) r (t) = t i + t j + tk

a. Which projectile is launched from the top of the tower and goes downward? When and where does it hit the ground?
b. Which projectile hits the top of the tree? When? From where is it launched?
c. Which projectile is not launched from somewhere on the tower and hits the tree? Where and when does it hit the tree? The projectile hits the tree at point (x, y, z) = at time t = .

Utah's great salt lake has an average salinity seven times higher than that of the oceans. very few multicellular organisms live in this harsh environment. an example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. these brine shrimp must available hint(s)utah's great salt lake has an average salinity seven times higher than that of the oceans. very few multicellular organisms live in this harsh environment. an example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. these brine shrimp must pump water back into their cells to counter its loss due to osmosisactively pump water back out of their cells to counter its inflow due to osmosissynthesize membranes that are impermeable to substances that upset osmotic balanceactively pump salt back out of their cells to counter its inflow due to osmosis

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.