question_answer 17)

A rocket is fired vertically with a speed of 5 km from the earth's surface. How far from the earth does the rocket go before returning to the earth ? Mass of the earth =  mean radius of earth =  

Answer:

Let the rocket be fired with velocity from the surface of earth and it reaches a height h from the surface of earth where its velocity becomes zero. Total energy of rocket at the surface of earth =  At the highest point, Total energy = K.E. + P.E. = 0 + According to law of  conservation of energy. Or         Or  Or   Or