In fig. 8-55, a block slides along a path that is without friction until the block reaches the section of length l = 0.75 m, which begins at height h = 2.0 m on a ramp of angle θ = 30°. in that section, the coefficient of kinetic friction is 0.40. the block passes through point a with a speed of 8.0 m/s. if the block can reach point b (where the friction ends), what is its speed there, and if it cannot, what is its greatest height above a?

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