question_answer

A body is projected with a speed u at an angle to the horizontal to have maximum range. What is its velocity at the highest point?                

Answer:

For range to be maximum \[\theta ={{45}^{o}}\]. At the highest point, the vertical component velocity is zero but the horizontal component velocity = \[u=\cos \theta =u\cos {{45}^{o}}=u/\sqrt{2}\].