Question

reading questions:

1. what is the difference between mass and weight?

1. upon what does weight depend?

1. complete the sentence: a planet’s gravitational field strength is always the same as its…

1. look at the g values in the table provided. why do you think some values are smaller, and some values are bigger? what might affect the value of g on different planets/dwarf planets?

mars	3.75
jupiter	26.0
saturn	11.2
uranus	10.5
neptune	13.3
pluto	0.61

Explanation:

1. Difference between mass and weight: Mass is the amount of matter in an object (scalar, constant everywhere), while weight is the force of gravity on an object (\(W = mg\), vector, depends on gravity).
2. What weight depends on: Weight depends on an object’s mass (\(m\)) and the gravitational field strength (\(g\)) of the planet/body it’s on (\(W = mg\)).
3. Completing the sentence: A planet’s gravitational field strength (\(g\)) is always the same as its surface gravity (or the acceleration due to gravity at its surface, since \(g\) defines how much 1 kg of mass weighs there, e.g., on Earth \(g \approx 9.8 \, \text{N/kg}\), meaning 1 kg weighs 9.8 N).
4. Why \(g\) values vary: \(g\) depends on a planet’s mass and radius (from the formula \(g = \frac{GM}{r^2}\), where \(G\) is the gravitational constant, \(M\) is the planet’s mass, and \(r\) is its radius). Larger mass or smaller radius increases \(g\); smaller mass or larger radius decreases \(g\). For example, Jupiter has high \(g\) (26.0) because it is very massive and relatively compact, while Pluto has low \(g\) (0.61) because it is small in mass and radius.

Answer:

s (for each sub - question):

1. Mass is the amount of matter in an object (constant), weight is the gravitational force on it (\(W = mg\), changes with gravity).
2. Weight depends on mass (\(m\)) and gravitational field strength (\(g\)) (formula \(W = mg\)).
3. A planet’s gravitational field strength is always the same as its surface gravity (or acceleration due to gravity at its surface).
4. \(g\) values vary because of a planet’s mass and radius (from \(g=\frac{GM}{r^2}\))—more mass or smaller radius increases \(g\), less mass or larger radius decreases \(g\).