Question 1 Report
A delivery truck is shown on Earth and on the Moon. The truck and its cargo have a combined mass of 4500 kg.
What is the difference in the weight of the truck between Earth and the Moon?
Weight on Earth: WE = m × gE = 4500 kg × 9.8 N/kg = 44 100 N. Weight on the Moon: WM = m × gM = 4500 kg × 1.6 N/kg = 7200 N. The difference in weight is 44 100 N - 7200 N = 36 900 N.
Mass remains 4500 kg in both locations because mass is a measure of the quantity of matter in an object and does not depend on gravity. Weight, however, is the gravitational force on that mass and changes with the local gravitational field strength. The Moon's much weaker gravity (1.6 N/kg compared to Earth's 9.8 N/kg) means the truck weighs far less there.
A common mistake is to subtract the two values of g first and then multiply by the mass: (9.8 - 1.6) × 4500 = 8.2 × 4500 = 36 900 N. This shortcut gives the same result because multiplication distributes over subtraction, but students should understand both approaches.
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