5 A student investigates the motion of different falling masses by measuring the time taken for empty cupcake cases to fall from a window.
(a) The student drops one case from the window.
He repeats the experiment with two cases stuck together, then with three cases
and then with four.
Name two measuring instruments that he would need for his investigation.

An observer that stands still as the electron moves by him, will observe

Two thin 80.0- cm rods are oriented at right angles to each other. each rod has one end at the origin of the coordinates, and one of them extends along the x- axis while the other extends along the yaxis. the rod along the x- axis carries a charge of - 15.0 μ c distributed uniformly along its length, and the other rod carries 15.0 μ c uniformly over its length. find the magnitude and direction of the net electrical force that these two rods exert on an electron located at the point (40.0 cm, 40.0 cm). (e

Choose all the answers that apply. our solar system: is in a spiral galaxy no longer includes pluto is made mostly of empty space is in the andromeda galaxy is the only known system that supports life