Question

For its size, the common flea is one of the most accomplished jumpers in the animal world. A 1.80 mm-long, 0.510 mg critter can reach a height of 18 cm in a single leap.

A) Neglecting air drag, what is the takeoff speed of such a flea? 1.88m/s


B) What's the kinetic energy of this flea at takeoff and its kinetic energy per kilogram of mass? (K = __ J)

C) K/m = __ J/kg

D) If a 69 kg, 2.0m-tall human could jump to the same height compared with his length as the flea jumps compared with its length, how high could he jump? (h = __ m)

E) And what takeoff speed would he need? (v = __ m/s)

F) Most humans can jump no more than 60 cm from a crouched start. What is the kinetic energy per kilogram of mass at takeoff for such a 69 kg person? (K/m = __ J/kg)

G) Where does the flea store the energy that allows it to make such a sudden leap?

Answer 1

A) 1.88m/s
\[v _{i} = \sqrt{2gh} \]