BIO A trap-jaw ant snaps its mandibles shut at very high speed, a good trait for catching small prey. But an ant can also slam its mandibles into the ground; the resulting force can launch the ant into the air for a quick escape. A 12 mg ant hits the ground with an average force of 47 mN for a time of 0.13 ms; these are all typical values. At what speed does it leave the ground

Final velocity (v) = 0.509 m/s (Approx)

Explanation:

Ant use impulse power

Given:

Mass of ant = 12 mg = 12 × 10⁻⁶ kg

Average force = 47 mN = 47 × 10⁻³ N

Initial velocity(u) = 0

Time taken = 0.13 ms = 0.13 × 10⁻³ s

Find:

Final velocity (v)

Computation:

Force × Time =  change in momentum

(47 × 10⁻³ N)(0.13 × 10⁻³ s) = mv - mu

(47 × 10⁻³ N)(0.13 × 10⁻³ s) = m(v - u)

6.11 × 10⁻⁶ = 12 × 10⁻⁶(v - 0)

6.11 = 12 v

Final velocity (v) = 0.509 m/s (Approx)

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more