Fleas have remarkable jumping ability. a 0.60 mg flea, jumping straight up, would reach a height of 40 cm if there were no air resistance. in reality, air resistance limits the height to 20 cm . part a what is the flea's kinetic energy as it leaves the ground?

To answer, we determine the velocity of the flea when it leaves the ground. Using the given value for distance, the velocity can be determined through the equation,

                     2a d = (Vf)² - (Vi)²

where a is the acceleration due to gravity, d is distance, Vf is the final velocity which is equal to zero and Vi is the initial velocity. Substituting the known values,

               2(9.8 m/s²)(40cm/100cm) = (Vi)²

The value of Vi from the equation is 2.8 m/s. 

The equation for determining the kinetic energy is:
                   KE = 0.5mv²

Substituting,
                  KE = 0.5(0.60 x 10^-3g)(1 kg/1000g)(2.8 m/s)²
                        KE = 2.352 x 10^-6 J