question_answer 2)

A pebble of mass 0.05 kg is thrown vertically upwards. Give the direction and magnitude of the net force on the pebble (i) during its upward motion. (ii) during its downward motion. (iii) at the highest point where it is momentarily at rest. Do your answers alter if the pebble were thrown at an angle of say 45° with the horizontal direction ? Take  

Answer:

Here m = 0.05 kg, (i) Net force on the pebble = mg  vertically downwards (iii) Net force on the pebble  vertically downwards The answers will not alter if the pebble were thrown at an angle of 45° with the horizontal because the horizontal component of velocity remains constant.