Mass and weight：練習題

Which statement correctly defines the weight of an object?

An object is suspended from a spring balance on Earth, where the gravitational field strength is \(9.8\text{ N/kg}\). The balance shows a reading of \(49\text{ N}\). The object is then taken to the Moon, where the gravitational field strength is approximately \(1.6\text{ N/kg}\).

What are the mass and the weight of the object on the Moon?

An object has a weight of \(600\text{ N}\) on Earth, where the gravitational field strength is \(10\text{ N/kg}\). The object is transported to Planet X, where the gravitational field strength is \(4.0\text{ N/kg}\).

What are the mass and weight of the object on Planet X?

Which statement defines the mass of an object?

An astronaut has a mass of \( 80\text{ kg} \). The gravitational field strength on the Moon is \( 1.6\text{ N/kg} \).
What is the weight of the astronaut on the Moon?

An object weighs \(49\text{ N}\) on Earth, where the gravitational field strength \(g\) is \(9.8\text{ m/s}^2\). Calculate the mass of the object and state whether this mass would change if the object were moved to the Moon.

A sample of rock has a mass of \(2.5\text{ kg}\). The gravitational field strength \(g\) on Earth is \(9.8\text{ N/kg}\).

(a) Define the term weight.
(b) Calculate the weight of the rock on Earth.
(c) On a different planet, the weight of the same rock is \(40\text{ N}\). Calculate the gravitational field strength of this planet.

An astronaut has a mass of \(75 \text{ kg}\).

(a) Define mass and weight, and state the SI unit for each.

(b) Calculate the astronaut's weight on Earth, where the gravitational field strength \(g\) is \(9.8 \text{ N/kg}\).

(c) The gravitational field strength on the Moon is approximately \(1.6 \text{ N/kg}\). Calculate the astronaut's weight on the Moon.

(d) Explain why the astronaut's mass remains constant while their weight changes when they travel from Earth to the Moon.