Physics: Matter and Forces

Question 1

Be able to distinguish between the mass and weight of an object.

Answer 1

Mass doesn’t change no matter where you are in the universe. Weight changes based on the gravitational field.

Question 2

Know that the Earth is the source of a gravitational field.

Answer 2

The Earth is the source of a gravitational field.

Question 3

Describe, and use the concept of, weight as the effect of a gravitational field on a mass.

Answer 3

weight = mass x gravity

Question 4

Describe an experiment to determine the density of a liquid and of a regularly shaped solid

Answer 4

density = mass / volume or d = m / V

Question 5

Describe the determination of the density of an irregularly shaped solid by the method of displacement, and make the necessary calculation.

Answer 5

Put water in a measuring cylinder or otherwise. Record initial volume as v1. Drop solid in. Record this volume as v2. Do equation v2 - v1 for the volume. Place the solid on a scale to calculate the mass.

Question 6

Know that a force is measured in newtons (N).

Answer 6

Force is measured in newtons (N)

Question 7

Describe how forces may change the size, shape and motion of a body.

Answer 7

Bending, twisting, compression, extension are the main ways for a body to change size, shape and motion.

Question 8

State Hooke’s Law and recall and use the

expression: force = constant × extension (F = kx).

Answer 8

Hooke’s Law is, as the weight increases so does the extension.
force = constant x extension

Question 9

Recognise the significance of the term ‘limit of proportionality’ for an extension / load graph.

Answer 9

As the spring reaches its limit, it stops obeying Hooke’s Law and can’t return to its original shape.