A particle is projected with a speed u at angle `theta` with the horizontal. Consider a small part of its path ner the highest position and take it approximately to be a circular arc. What is the rdius of this circle? This radius is called the adius of curvature of the curve at the point.

Answer

A, B, C

Explanation

Particle is projected with speed u at an angle `theta`. At the highest point the veticasl component of velocity is 0.
So at the point, velocity`=ucostheta`
Centripetal force `=(mu^2cos^2theta)/r`
At highest point `mg=(mv^2)/r=(mu^2 cos^2theta)/r`
`rarr r=(u^2cos^2theta)/g`