Why aren’t descriptive investigations repeatable

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

The position of a crate sliding down a ramp is given by x=(0.05t^3) m, y=(1.7t^2) m, z=(6−0.85t^5/2) m, where t is in seconds. (a) determine the magnitude of the crate's velocity when t = 2 s. (b) determine the magnitude of the crate's acceleration when t = 2 s.

Which lists the organs in the correct order as food passes from the mouth to anus?