question_answer

   (i) At some moment, two giant planets Jupiter and Saturn of the solar system are in the same line as seen from the earth. Find the total gravitational force due to them on a person of mass 50 kg on the earth. Could the force due to the planets be important? Mass of the Jupiter = 2 x 1027 kg Mass of the Saturn = 6 x 1026 kg Distance of Jupiter from the earth Distance of Saturn from the earth Gravitational constant, Acceleration due to gravity on the earth (ii) A bag of sugar weighs W at a certain place on the equator. If this bag is taken to Antarctica, will it weigh the same or more or less. Give a reason for your answer.  

Answer:

                  (i) (a) Gravitational force action on the 50 kg mass on the earth = mg = 50 x 9.8 = 490 N. (1/2) (b) Gravitational force acting on the 50 kg mass due to Jupiter (1/2) (c) Gravitational force acting on the 50 kg mass due to Saturn Total gravitational force due to the Jupiter and the saturn                                                      (1/2) Thus, the combined force due to the planets   Jupiter and Saturn  N is negligible as  compared to gravitational force due to the earth.  (ii) We know that, g at equator is less than g at poles  (Antartica).                                      Thus, weight at equator is less than weight at    pole (Antartica).                                 A bag of sugar weights W at a certain place on the equator. If this bag is taken to Antartica, it   will weigh more due to greater value of g.(1)