Mass & Inertia Flashcards

All 5 cards in this deck

What is inertial mass?

A measure of how difficult it is to change the velocity of an object, including changing it from rest.

How is inertial mass defined as a ratio?

inertial mass = force ÷ acceleration

What are the steps to calculate the inertial mass of an object?

e.g. a force of $20\ \mathrm{N}$ gives an acceleration of $4\ \mathrm{m/s^2}$

1. Use inertial mass $=$ force $\div$ acceleration
2. Divide: $20 \div 4 = 5\ \mathrm{kg}$

True or false? An object with a larger inertial mass needs a larger force to give it the same acceleration.

True. Force = inertial mass × acceleration, so more mass needs more force for the same acceleration.

True or false? Inertial mass only describes how hard it is to speed an object up.

False. It describes how hard it is to make any change in velocity — speeding up, slowing down or changing direction.