The position of a baseball (in ft) is represented by r(t) = 50 2 ti + (4 + 50 2 t − 16t2)j. Find the arc length of the trajectory (flight) of the baseball. (Let t = 0 represent when the ball is hit. Let j = 0 be ground level. Round your answer to one decimal place.)

The physical fitness of an athlete is often measured by how much oxygen the athlete takes in (which is recorded in milliliters per kilogram, ml/kg). the mean maximum oxygen uptake for elite athletes has been found to be 60 with a standard deviation of 7.2. assume that the distribution is approximately normal.

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.

∆red ≅ ∆ by rule will give brainiest if possible