A train is traveling south at constant speed 12.0 m/s. Then the brakes are applied & it slows down with a constant acceleration to a speed of 3.00 m/s in a time of 9.00 s. (a) Draw a graph of speed versus time for a 12-s interval (starting 2 s before the brakes are applied and ending 1 s after the brakes are released).
(b) What is the acceleration of the train during the 9.00-s interval?
(c) How far does the train travel during the 9.00 s?

Astone is thrown with a speed v0 and returns to earth, as the drawing shows. ignore friction and air resistance, and consider the initial and final locations of the stone. which one of the following correctly describes the change δpe in the gravitational potential energy and the change δke in the kinetic energy of the stone as it moves from its initial to its final location? options a.δpe = 0 j and δke = 0 j b.δpe is positive and δke is negative c.δpe = 0 j and δke is positive d.δpe is negative and δke is positive e.δpe = 0 j and δke is negative