A roller coaster car picks up speed as it rolls down the slope. As it starts down the slope, its speed is 4 m/s. It accelerates at a rate of 6 m/s2. What is its velocity after 3 seconds?

A33.1 g copper object is launched from a 1.5 m 30° steel incline positioned on the floor by being pulled up a string attached to a 50.0 g mass suspended vertically over a pulley. the object is projected towards a glass table where it lands when it is at the point along its trajectory with the lowest speed. it comes to a halt when it clears the opposite edge of the table. it then falls and lands on 9 physics texts each 5 cm thick that are stacked on the floor on the opposite side of the table. assume that the table does not have a ledge and the rectangular object experiences 0.05 n of air resistance as it falls towards the books. how far and how long did the object travel and how fast does it hit the books. assume that at the moment the copper object leaves the incline, the massless string and ideal pulley break off

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.

Hunter is in lab. he clears a spot on his lab bench to start working. he also puts his lab coat and goggles on. he then identifies where all of the safety equipment is. he notices his station is next to the fume hood, which ventilates the chemicals stored there. the noise of the fume hood was bothersome, so hunter turned it off. which could be an error in his set-up? he should not turn off the fume hood.  he should wait to put on his coat until after the directions are given.  he should wait to put on his goggles until after the directions are given.  he should not sit next to the fume hood.