Question

A body is projected up a smooth inclined plane (length = 20√2 m ) with velocity u from the point M as shown in the figure. The angle of inclination is 45° and the top is connected to a well of diameter 40 m. If the body just manages to cross the well, what is the value of v  

(a) 40 m/s

(b) 40 √2  m/s

(c) 20 m/s

(d) 20 √2 m/s

Answer 1

Correct option (d) 20 √2 m/s 

Explanation:

At point N angle of projection of the body will be 45°. Let velocity of projection at this point is v. If the body just manages to cross the well then Range = Diameter of well

But we have to calculate the velocity (u) of the body at point M. For motion along the inclined plane (from M to N) 

Final velocity (v) = 20 m/s, 

acceleration (a) = – g sinα = – g sin 45^o, distance of inclined plane  (s)