M3 - Newton's Laws Flashcards
1
Q
What is mg?
A
Weight of a partical
2
Q
Finish the equation:
F = … x …
A
F = m x a
Force = mass x acceleration
3
Q
What does force represent?
A
Resultant overall force
4
Q
What must be true if an object is in equilibrium?
A
- Is at rest or has constant velocity
- Horizontal components are equal
- Vertical components are equal
5
Q
If particles are connected by a light inextensible string, what can we assume?
A
- String has no weight
- Tension remains constant throughout
- Acceleration is equal for all components
6
Q
How can you find different forces in a question about trailers?
A
- Consider the whole system as a whole (for acceleration or driving force)
- Consider each object separately (for tensions)
7
Q
How can you find different forces in a question about lifts?
A
- Consider lift and person separately
- Consider lift and person as a whole
8
Q
What do you need to do on a question about pulleys?
A
- Create equations of motion for each mass
- Solve simultaneously to find tension and acceleration
9
Q
In a question about pulleys, what do you need to do if the string breaks?
A
- a becomes 9.8 (+ or - depending on which way you consider up)
- Tension is no longer applied
10
Q
In a question about pulleys, what do you need to do if one mass hits a surface?
A
- Redo F = ma equation without tension to find the new acceleration
