Materials

Question 1

What is density?

Answer 1

mass per unit volume

Question 2

How would you measure the density of a regular solid?

Answer 2

measure its mass using a balance. measure its dimensions using vernier callipers. Density = m/v

Question 3

How would you measure the density of a liquid?

Answer 3

measure the mass of an empty measuring cylinder, fill with liquid, and measure the new mass. This difference in mass is the mass of liquid. Volume of liquid is given on measuring cylinder. Density = m/v

Question 4

How would you measure the density of an irregular solid?

Answer 4

measure the mass of the object using a balance. immerse the object in a measuring bath and measure the increase in the volume, this increase is equal to the volume of the object. Density = m/v

Question 5

What is an alloy?

Answer 5

A solid mixture of two or more metals

Question 6

Define Hooke’s law

Answer 6

the force needed to stretch a spring is directly proportional to the extension of the spring from its natural length.

Question 7

Sketch a typical tensile stress/tensile strain graph

Answer 7

see textbook

Question 8

What is the limit of proportionality?

Answer 8

the point beyond which Hooke’s law is no longer true when stretching a material.

Question 9

What is the elastic limit?

Answer 9

the point beyond which the material you are stretching becomes permanently stretched so that the material does not return to its original length when the force is removed.