Physics 1121 Quiz 1 Flashcards
Physics
the branch of science that deals with matter and energy and their relationship to each other.
Radiologic Physics
the branch of physics dealing with the origin, nature, and behavior of x-rays.
Health Physics
the branch of physics dealing with the protection of people from over-exposure to radiation.
Also known as radiation protection
Technology
a practical application of the laws of physics
Mechanics or kinematics
Study of motion
3 mechanical laws
Classical or Newtonian
Relativistic
Quantum
How objects move and transfer force during motion
Law of Inertia or Newton’s 1st Law
- An object at rest will tend to remain at rest while an object in straight line motion will tend to remain doing so.
- If no outside force acts on an object, there will be no change in its motion.
- All matter has inertia
- Anytime an object changes direction, it must lose energy to do so.
- The amount of inertia in a moving object can be measured by momentum.
Momentum formula
Momentum (p) = mass x velocity
The greater the value for momentum, the more energy that is required to change the motion of an object.
Law of Acceleration or Newton’s 2nd Law
The acceleration of an object is directly proportional to the net force acting upon it and inversely proportional to the mass of the object.
Acceleration formula
Acceleration = force/mass
The more mass an object possesses, the more force is needed to accelerate the object.
Distance formula
d = ½ a t^2
Law of Interaction or Newton’s 3rd Law
When one object exerts a force on a second object, that second object will exert an equal and opposite force upon the first.
Important in understanding collisions
Elastic
collisions that conserve both momentum and KE, such as billiard balls and atoms and sub-atomic particles (the only true elastic collisions)
Inelastic
momentum is conserved but a change in velocity takes place.
Newtons 3rd law formula (Collisions)
Mass x velocity1 = mass x velocity2
