A chameleon can accelerate its tongue in order to catch an insect at an impressive rate of 500m/s^2. How quickly must a fly located at 5cm from the chameleon react if it is to escape?

Given:

Vi = 0

V_f = ?

x_i = 0

x_f = 5 cm

a = 500m/s^2

Using the equation:

V_f²=V_i²+2a(x_f-x_i)

V_f=70.71m/s

 

Could someone please double check this answer for me.

 

Thanks!

Edited October 12, 20178 yr by Chu

does it seem reasonable?

If that is the final velocity the average would be half that...around 35m/s...and it would have taken about a seventh of a second to get to 70.71m/s

You might want to double check the decimal place of your result...

 

I see what I did wrong. I didn't do parenthesis first and went to multiplication.

4 minutes ago, Chu said:

I see what I did wrong. I didn't do parenthesis first and went to multiplication.

Not sure what you mean exactly. What was your result?

You also haven't answered the question.

Really only enough information to answer "time required to react before getting eaten"

I was using the wrong equation! 

using 

X_f=1/2at² 

0.05=1/2(500)*t²

0.05=250*t²

t²=0.0002      square this to get:

t=0.014 s