Two spaceships approach the earth from opposite directions. according to an observer on the earth, ship a is moving at a speed of 0.753c and ship b at a speed of 0.851c. what is the velocity of ship a as observed from ship b

Amplitude is a measure of a waves a; speed b; distance c; energy d; frequency

An object has a weight of 500 on earth what is the mass of this object

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