A heavy particle is projected from a point on the horizontal at an angle `45^(@)` wil the horizontal with a speed of 20 m/s. Then the radius of the curvature of its path at the instant of crossing the same horizontal is ______

Options

A. `10 sqrt(2)`
B. `40 sqrt(2)`
C. `20 sqrt(2)`
D. none of these

Answer

B

Explanation

Radial acceleration at the point of landing
`a_(n) = g cos 45 = (u^(2))/(r)`
`rArr r =(u^(2))/(g cos45)=((20)^(2))/(10xx1//sqrt(2))=40 sqrt(2)`