Question

a shell of mass 50 kg is fired from a point on a level ground at an angle of 60° above the horizontal with a speed 200 m/s .neglecting air resistance ,calculate its kinetic energy of [i]its highest point of motion
[ii]a point of a horizontal distance of 1.1 km from the point of projection

Answer 1

Answer:

i) KE at the highest position=1/2mu²cos²theta

                                                =1/2*50*200²*cos²60

                                                =25*40000*(1/2)²

                                                 =25*40000*1/4

                                                 =25*10000

                                                 =250000 J

ii)KE=1/2mv²

       =1/2*50*200²

       =25*40000

        =1000000 J

Explanation: