A man carries 40 tiles from the ground to the roof of a house. each tile has a mass of 1.5 kg . the roof of the house is 20 m above the ground. how much work does the man do against graviy on the tiles in carrying the roof? ​

Abaseball is thrown from the outfield toward the catcher. when the ball reaches its highest point, which statement is true? (a)its velocity is not zero, but its acceleration is zero. (b) its velocity and its acceleration are both zero. (c) its velocity is perpendicular to its acceleration. (d) its acceleration depends on the angle at which the ball was thrown. (e) none of the above statements are true.