Aperson pushes a crate up a 4-m high ramp for a distance of 18m.

a) what is the mechanical advantage of the ramp?

b) how hard does the person have to push if the crate weights 400 n

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

Identify some abiotic characteristics of the tundra biome.

If the specific heat of a metal is 0.850 j/g °c, what is its atomic weight?