You throw a ball straight up with an initial velocity of 14.1 m/s. It passes a tree branch on the way up at a height of 7.00 m. What is the velocity (in m/s) of the ball when it hits the tree for the second time?

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

An object's buoyant force and weight mean the same thing.a. trueb. false

If anyone who can me with this hw? i would really appreciate it