A traveller carries a suitcase of mass 18kg from the equator to the North Pole.
(i) Explain briefly why the weight of the same object is not exactly the same at the equator and at the poles.
(ii) Taking the value of acceleration due to gravity as 9.78m/s2 at the equator and 9.83m/s2 at the poles, calculate the weight of the suitcase at both locations.
(iii) Determine the percentage difference between the two weights (correct to two decimal places).
(iv) Will the mass of the suitcase change between the two places? Give a reason for your answer.