Forces And Newton's Laws Flashcards
What are Newton’s Laws?
An object will remain in constant motion or stationary unless a resultant force acts on it
F=ma
Two bodies in contact will exert an equal and opposite force
What is the normal reaction force
Force opposing weight at 90° to surface
What does a light in extensible string suggest
Light= acceleration of mass are the same
In extensible= same tension throughout
What assumptions are usually made in force diagrams
No air resistance acts on the object or if it does it is constant
All forces act on centre of mass
No friction (if smooth surface)
What does having a smooth pulley result in
Same tension throughout string
When two masses are on opposite ends of the string around a smooth pulley what is the initial acceleration of the lighter mass as the heavier one hits the ground?
The same as the final velocity of the heavier mass as it hits the ground
When an object is on a slope in what direction will the weight act
Vertically downwards
How do you determine whether a rod is providing tension or compression
Work out the tension in the rod away from the object
If negetive then T Is acting towards object (compression)
If positive then T is acting away from object (tension)
