Question

Fleas are agile, wingless insects that feed on the blood of their hosts. Although they are typically 2–3 mm long with a mass of 3.9×10−4 kg , they have an astonishing ability to jump when threatened. Their propulsion, which can briefly produce accelerations more than 100 times that of gravity, comes not from muscles but, in fact, from an elastomeric protein called resilin, which acts as a spring. Given that the typical launch velocity of a flea is about 1 m/s, what total energy must be stored in the resilin just before the flea jumps?

Answer 1

Answer:

$E = 1.95 \times 10^{-4} J$

Explanation:

As we know that the mass of the fleas is given as

$m = 3.9 \times 10^{-4} kg$

now the speed of the fleas is given as

$v = 1 m/s$

now just before it will jump let say it has some energy E

so as per energy conservation law we can say that this total initial energy will convert into its kinetic energy just after the jump

so the initial total energy is given as

$E = \frac{1}{2}mv^2$

$E = \frac{1}{2}(3.9 \times 10^{-4})(1^2)$

$E = 1.95 \times 10^{-4} J$