Question

6. The average speed of a nitrogen molecule in air is about

6.70 1 102 m/s, and its mass is 4.68 1 10#26 kg. (a) If it

takes 3.00 1 10#13 s for a nitrogen molecule to hit a wall

and rebound with the same speed but moving in the op-

posite direction, what is the average acceleration of the

molecule during this time interval? (b) What average

force does the molecule exert on the wall?

Answer 1

Given,

Velocity$(v_1)=6.70\times 10^{2} m/s$

After the hitting the wall, it rebounds with the same speed in opposite direction,

$v_2=-6.7\times 10^{2}m/s$

Mass $(m)=4.68\times 10^{-26}kg$

Time $(t)=3.0\times 10^{-13}s$

$a=\frac{dv}{dt}=\frac{v_2-v_1}{t}$

$=\frac{-6.7\times 10^2-6.7\times 10^2}{3.0\times 10^{-13}} m/s^2$

$=-4.47\times10^{15} m/s^2$

Average force $(F)= ma$

$F=4.68\times 10^{-26}\times 4.47\times 10^{15}N$

$=20.91\times 10^{-11}N$