An object has a mass of 60 kg on the Earth. Approximately what will be its weight on the Moon, where the acceleration due to gravity is about one sixth of that on Earth (answer in newton, N)?

Introduction / Context:
This question examines your understanding of the difference between mass and weight and how weight depends on the local acceleration due to gravity. Mass is a measure of the amount of matter in an object and remains the same everywhere. Weight, however, is the gravitational force acting on that mass and changes when the gravitational field changes, such as moving from Earth to the Moon. Many competitive questions ask you to estimate weight on different celestial bodies using simple ratios.

Given Data / Assumptions:

• Mass of the object, m = 60 kg.
• Acceleration due to gravity on Earth, g_E, is about 9.8 m/s^2, commonly approximated as 10 m/s^2 in simple problems.
• Acceleration due to gravity on the Moon, g_M, is about one sixth of that on Earth.
• We are asked for the weight on the Moon in newton (N), where weight W = m * g.

Concept / Approach:
Weight is defined as the force with which a planet or celestial body attracts a mass, given by W = m * g. On Earth, a 60 kg mass has a weight approximately W_E = 60 * 10 = 600 N. On the Moon, where gravity is about one sixth of Earth gravity, the weight will be roughly one sixth of 600 N. That is 600 / 6 = 100 N. The mass of the object does not change, only the local gravitational acceleration does. Therefore, the approximate weight on the Moon is 100 N.

Step-by-Step Solution:
Step 1: Write the expression for weight: W = m * g. Step 2: For Earth, take g_E ≈ 10 m/s^2. Then W_E = 60 kg * 10 m/s^2 = 600 N. Step 3: The Moon gravity is g_M = g_E / 6, which is about 10 / 6 ≈ 1.67 m/s^2. Step 4: Compute the weight on the Moon: W_M = m * g_M = 60 kg * (10 / 6) m/s^2 = 600 / 6 N. Step 5: Evaluate 600 / 6 = 100 N. Step 6: Compare with options and select 100N as the best approximate value.

Verification / Alternative check:
A quick ratio method can also be used. Since weight is proportional to g and the Moon gravity is one sixth of Earth gravity, the weight on the Moon must be one sixth of the weight on Earth. If the weight on Earth is about 600 N, dividing by 6 gives 100 N. This simple proportion directly yields the same answer without detailed arithmetic, confirming the result.

Why Other Options Are Wrong:
60N is too small because it corresponds to one tenth of the Earth weight, whereas the Moon gravity is one sixth, not one tenth, of Earth gravity. 600N is the approximate weight on Earth, not on the Moon. Since Moon gravity is weaker, the weight must be less than this. 10N is far too small and would correspond to a mass of only about 1 kg under Earth gravity, not 60 kg under Moon gravity.

Common Pitfalls:
Some students mistakenly think that mass changes when moving from Earth to the Moon and try to adjust the mass instead of adjusting gravity. Always remember that mass remains constant, while weight changes with local gravitational acceleration. Another common error is to forget the one sixth factor and to apply the full Earth gravity value. Using the ratio method and keeping the distinction between mass and weight clear helps avoid these mistakes.

Final Answer:
A mass of 60 kg will have an approximate weight of 100N on the Moon.