- Exercise 9:
Billy, a mountain goat, is rock climbing on his favorite slope one sunny spring
morning when a rock comes hurtling toward him from a ledge 40.0 m above.
Billy ducks and avoids injury. a) How fast is the rock traveling when it passes
Billy? b) How does this speed compare to that of a car traveling down the
highway at the speed limit of 25 m/s (equivalent to 55 mi/h)?

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)

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)