Chapter 7- Laws of Motion and Momentum Flashcards
Newton’s First Law
An object will remain at rest or continue to move with constant velocity unless acted upon by a resultant force
Newton’s Third Law
When two objects equal interact they exert two equal (magnitude and type) forces on each other
Four fundamental forces that explain all interactions
Gravitational
Electromagnetic
Strong nuclear
Weak nuclear
The two nuclear have incredibly small range
Momentum
mass x velocity
units kgms^-1
vector quantity
If objects are travelling in opposite directions
You must make one of their velocities negative
Conservation of Momentum
For a system of interacting objects, the total momentum in a specific direction remains constant, as long as no external forces act on a system
Explosions
Scenarios that have zero momentum before and after the incident
Elastic collisions
The total kinetic energy of the system will remain constant
Inelastic collisions
Some of the kinetic energy will be lost
Newton’s Second Law of Motion definition
The net force acting on an object is directly proportional to the rate of change of momentum and is in the same direction
Newton’s Second Law of Motion rearranged equation
F = Δp/Δt
When does F=ma work?
When a constant force acts on a constant mass
Impulse
The product of force and the time for which it acts on an object. Equal to the change in momentum
How to find impulse from a force-time graph?
The area under the curve
Impulse equation
Δp = F x Δt
