Which correctly describes the law of conservation of energy?
question 6 options:
energy can be created or destroyed, but cannot change from one form to another.
energy can be created or destroyed, and can change from one form to another.
energy cannot be created or destroyed, but can change from one form to another.
energy cannot be created or destroyed, and cannot change from one form to another.

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

Object a has a length of 3 cm, a width of 2 cm, and a height of 4 cm. object b is dropped into a graduated cylinder. it displaces 19 ml of water. the volume of object a is: a: greater than the volume of object b b: less than the volume of object b c: equal to the volume of object b

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?