2. A child throws a 0.200 kg rock at a tree. When the rock leaves the child's hand, it is moving at 20 m/s and is located 1.5 m above the ground. a. Find the total mechanical energy of the rock.
b. How high above the ground does the rock strike the tree if it is moving at 10 m/s at the instant it hits the tree.

Now that the first three steps have been explained, identify the next three steps, in order. calculate the magnitude of r sum vector components calculate a and b magnitudes calculate the direction of r, calculate x,y components step 4 step 5 step 6

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.

Consider a small frictionless puck perched at the top of a fixed sphere of radius r. if the puck is given a tiny nudge so that it begins to slide down, through what vertical height will it descend before it leaves the surface of the sphere? [hint: use conservation of energy to find the puck's speed as a func e conservation of energy to find the puck's speed as a function of its height at what value of this normal force does the puck leave the sphere? ] here on the puck.