Chapter 7 - Momentum Flashcards
What is Newton’s First Law?
An object will remain at rest or at a constant velocity unless it is acted upon by a resultant force.
What is Newton’s Second Law?
The net force acting upon an object is proportional to the rate of change in momentum.
What is Newton’s Third Law?
When two objects interact, they exert equal and opposite forces.
What are the four Fundamental forces?
Gravitational - produced with a mass in a gravitational field.
Electromagnetic - force between charged particles.
Strong Nuclear - attractive force between protons and neutrons that keep the nucleus together.
Weak Nuclear - governs certain radioactive decays.
Define Momentum
Momentum is defined as the product of mass and velocity of an object. Its units are kgms^-1.
p = mv
mass in kg
Velocity in ms^-1
What is the principle of conservation of momentum?
For a system of interacting objecting, the total momentum in a specific direction remains constant, as long as no external forces act on the system.
Is momentum a vector or a scalar quantity?
Momentum is a vector quantity as it is a product of velocity mean it can be positive or negative as a specified direction.
How can you investigate momentum?
Momentum can be investigated on an air tract using light gate or a motion sensor set up with a data logger. Due to the air track having little resistance you can clear see what is conserved in elastic and inelastic collisions.
What is the difference between elastic and inelastic collisions?
In both elastic and inelastic collisions total momentum and total energy are conserved.
However, in elastic collision total kinetic energy is also conserved.
Defined an impulse?
Impulse of a force is defined as the product of force and the time for which the force acts on an object.
Impulse = Force x time
Impulse = change in momentum
What can be calculated from a force-time graph?
The area under a force-time graph is equal to the impulse.
Derive F =ma from Impulse = Force x Time
Impulse = Force x Time Force = Impulse / Time Impulse = Change in momentum Force = Change in momentum / Time Momentum = Mass x Velocity Force = Mass x Velocity / Time Velocity / Time = Acceleration Force = Mass x Acceleration`
How can the momentum of a photon be calculated?
Momentum = Planck’s Constant / Wavelength
Planck’s Constant - 6.63 x 10^-34
