Aperson throws a balloon straight down above level ground. the balloon bounces back up into the air. drag force is significant when the balloon is moving. verbally describe a free-body diagram for the balloon for each of the following times (you must include the force type, source, receiver, and direction for each force; relative magnitudes, when known, must be clear):

the balloon is being thrown down and is speeding up.
the balloon is in the air on its way down and is moving at constant speed.
the balloon has hit the ground and is instantaneously at rest as it reverses direction.
the balloon is in the air on its way back up and slowing down.
the balloon is in the air and is instantaneously at rest at the peak of its trajectory.

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 11.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.80 m/s; (b) he is then lifted at the constant speed of 4.80 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 78.0 kg rescue by the force lifting him during each stage

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 electron is traveling with initial kinetic energy k in a uniform electric field. the electron comes to rest momentarily after traveling a distance d. (a) what is the magnitude of the electric field