Weight, Mass, and Gravity

Question 1

What is Gravitational Force?

Answer 1

The Force of Attraction Between Masses

Gravity attracts all masses, especially noticeable with large masses like planets.

Question 2

What happens to objects on the surface of a planet due to gravity?

Answer 2

All things fall towards the ground

This is a direct effect of gravitational attraction.

Question 3

What is the difference between Weight and Mass?

Answer 3

Mass is the amount of ‘stuff’ in an object, while Weight is the force acting on an object due to gravity

Mass remains constant regardless of location, but weight varies with gravitational field strength.

Question 4

How does gravitational field strength vary?

Answer 4

It varies with location and is stronger closer to the mass causing the field

Larger masses also create stronger gravitational fields.

Question 5

What is the relationship between an object’s weight and the gravitational field strength at its location?

Answer 5

The weight of an object depends on the strength of the gravitational field at its location

This means weight changes with location, unlike mass.

Question 6

What is the weight of a 1 kg mass on the Moon and on Earth?

Answer 6

On Earth, about 9.8 N; on the Moon, about 1.8 N

This difference is due to the varying gravitational field strengths.

Question 7

What is Weight measured in?

Answer 7

Newtons

Weight is the force acting on an object due to gravity.

Question 8

What is Mass measured in?

Answer 8

Kilograms

Mass is measured using a mass balance.

Question 9

What is the formula to calculate Weight?

Answer 9

Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg)

For Earth, g = 9.8 N/kg and for the Moon, it is around 1.8 N/kg.

Question 10

How are Weight and Mass related?

Answer 10

Weight and Mass are directly proportional

Doubling the mass doubles the weight.

Question 11

What symbol represents the direct proportionality between Weight and Mass?

Answer 11

W ∝ m

This indicates that weight increases with mass.

Question 12

What is the Centre of Mass?

Answer 12

A point at which the whole mass of an object is concentrated

For uniform objects, this is at the center of the object.

Question 13

How is Weight measured?

Answer 13

Using a calibrated spring balance or newtonmeter

These instruments measure the force of gravity on an object.