A miner working in a deep vertical shaft finds that a tool shows a weight of 156N at a certain depth where the value of g has decreased to 7.8m/s2. Read the situation carefully and answer the questions that follow:
a. (i) Calculate the mass of the tool.
b. (ii) What would be the weight of the same tool at the Earth’s surface where g=9.8m/s2?
c. (iii) Explain why the weight of the tool changes with depth while its mass remains the same.