Inertia and Newton's Third Law Flashcards
1
Q
What is inertia?
A
The tendency to keep moving with the same velocity
2
Q
Describe what is meant by ‘inertial mass’.
A
A measurement of how difficult it is to change the velocity of an object
3
Q
What does Newton’s third law of motion say?
A
When two objects interact, the forces they exert on each other are equal and opposite
4
Q
How can inertial mass be found by using Newton’s second law?
A
- Inertial mass is the ratio of force over acceleration
- So, rearrange to find the mass - (m = F ÷ a)
5
Q
When is an object in equilibrium?
A
When the resultant force acting on it equals zero
6
Q
(Exam-style question)
A
7
Q
(Exam-style question)
Two students each stand at rest on a skateboard by a wall. They both push against the wall with a force of 24N. (Assume there is no friction between the skateboards and the ground)
Explain, in terms of forces, why the students would move away from the wall.
A
- As the students push the wall, the wall will exert an equal and opposite force on each student
- As there is no friction, each student will have a resultant force pushing them away from the wall which causes them to move
