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It has been claimed that an insect called the froghopper (Philaenus spumarius) is the best jumper in the animal kingdom. This insect can accelerate at 4 000 m/s2 over a distance of 2.0 mm as it straightens its specially designed " jumping legs." Assuming a uniform acceleration, what is the velocity of the insect after it has accelerated through this short distance.

Respuesta :

AMB000

Answer:

v=4m/s

Explanation:

The formulas for accelerated motion are:

[tex]v=v_0+at\\x=x_0+v_0t+\frac{at^2}{2}[/tex]

We can derive the formula [tex]v^2=v_0^2+2ad[/tex] from them.

We have:

[tex]v-v_0=at\\t=\frac{v-v_0}{a}[/tex]

And substitute:

[tex]x=x_0+v_0(\frac{v-v_0}{a})+\frac{a}{2}(\frac{v-v_0}{a})^2\\x-x_0=\frac{v_0(v-v_0)}{a}+\frac{(v-v_0)^2}{2a}\\2a(x-x_0)=2v_0(v-v_0)+(v-v_0)^2=2v_0v-2v_0^2+v^2+v_0^2-2vv_0=v^2-v_0^2[/tex]

Where in the first step of the last row we just multiplied everything by 2a. Since [tex]x-x_0[/tex] is the displacement d, we have proved that [tex]v^2=v_0^2+2ad[/tex]

We use then our values to calculate the final velocity when starting from rest, traveling a distance 0.002m with acceleration [tex]4000 m/s^2[/tex]:

[tex]v=\sqrt{v_0^2+2ad}=\sqrt{2(4000m/s^2)(0.002m)}=4m/s[/tex]