Question

ball of mass 200 gm is thrown upwards with an initial velocity of 30m/sec. What is its kinetic energy at the highest point of its path? What is the potential energy there?

Answer 1

Answer:

Since the ball is thrown upward so as per equation “v=u+at” by keeping value of v=0 ,u=30 and a=g(acceleration due to earth' gravity) we get to know that in approximately 3s (takeg=10m/s^2) the ball will stop and start moving downwards so then after 2 seconds its velocity 'v' will be v=u+at here u=0 so v will be 20m/s.Hence kinetic energy will be after 5s of throwing ball upwards 0.5*m*v^2 so it will be 0.2*20*20*0.5=40 joules(by taking g=10m/s^2)

so answer is 40 joules