A) greater
B) smaller
C) same
D) depends on height
Correct Answer: A
Solution :
When the raindrops attains terminal velocity the net force acting on the body is zero. \[\therefore \] \[W-T-F=0\] or \[F=W-T\] \[\Rightarrow \] \[6\pi \eta rv=\frac{4}{3}\pi {{r}^{3}}\rho g-\frac{4}{3}\pi {{r}^{3}}\sigma g\] \[=\frac{4}{3}\pi {{r}^{3}}(\rho -\sigma )g\] \[\therefore \] Terminal velocity \[v=\frac{2}{9}\frac{{{r}^{2}}(\rho -\sigma )g}{\eta }\] or \[v\propto {{r}^{2}}\] Hence, the impact speed of large raindrops is greater as compared to the small raindrops.
You need to login to perform this action.
You will be redirected in
3 sec
