Physics and Math Basics Flashcards
What are two different groups of units?
MKS: meters, kilograms and seconds
CGS (SI): centimeters, grams, and seconds
What are the units in a newton?
1 kg . m / s^2
What are the two units of force?
Dyne and newton
What are the units in a dyne?
1 g . cm / s^2
What are the two units of work and energy?
Erg and joule
What are the units of an erg?
1 g . cm^2 / s^2
What are the units of a joule?
- kg . m^2 / s^2
What are the two units for power?
erg/s and watt
What are the units of a watt?
- kg . m^2 / s^3
What is an angstrom?
10^-10 meters
What are 4 vector quantities?
- Displacement
- Velocity
- Acceleration
- Force
How do you apply the right hand rule when multiplying vectors?
- Point your thumb in the direction of A
- Extend your fingers in the direction of B
- Your palm is in the direction of the product C = AB
What is displacement?
The vector representation of a change in position
What is distance?
Scalar quantity that reflects the path traveled
What is velocity?
The vector representation of the change in displacement with respect to time
What is the average velocity?
Total displacement / total time
What is the average speed?
Total distance / total time
What is the instantaneous velocity?
Limit of the change in displacement over time as the change in time approaches 0
What is the instantaneous speed?
The magnitude of the instantaneous velocity vector
What is a force?
Any push or pull that has the potential to result in an acceleration
What is gravity?
The attractive force that opposes motion as a function of electrostatic interactions at the surface between objects
What is static friction?
Exists between two objects that are not in motion relative to each other
What is kinetic friction?
Exists between two objects that are in motion relative to each other
How many values can static friction take on? Depending on what?
Many depending on on the magnitude of the applied force
How many values can kinetic friction take on?
One; constant value
What does the coefficient of friction depend on?
The two materials in contact
Which is larger: the coefficient of static friction or the coefficient of kinetic friction? What does this mean?
The coefficient of static friction
It means it always requires more force to get an object to start sliding than it takes to keep an object sliding
What is mass a measure of?
The inertia of an object = its amount of material
What is weight?
The force experienced by a given mass due to the gravitational attraction of the earth
What is acceleration?
The vector representation of the change in velocity over time
Where is the center of mass of a uniform object?
At the geometric center of the object
What is the direction of frictional forces?
Opposite that of the movement
When no force is being applied, the velocity must be…
Constant
What does Newton’s first law state?
An object will remain at rest or move with a constant velocity if there is no net force on the object
What is another name for Newton’s first law?
Law of inertia
What does Newton’s second law state?
Any acceleration is the result of the sum of the forces acting on the object and its mass
What does Newton’s third law state?
Any 2 objects interacting with one another experience equal and opposite forces as a result of their interaction
What does linear motion include? (2)
- Free fall
2. Motion in which the velocity and acceleration are parallel or antiparallel
What does projectile motion contain?
x and y components
Assuming negligible air resistance, what is the only force acting on an object during projectile motion?
Gravity
What are inclined planes an example of?
Two-dimensional movement: parallel and perpendicular
What are the 3 dimensions of circular motion?
Radial and tangential dimensions
What is the only force acting in uniform circular motion?
Centripetal force
Where does centripetal force point?
Radially inward
Where does the instantaneous velocity vector point in circular motion?
Tangentially
What is the velocity when an object is at its maximum height in a parabolic pathway?
0
What happens in free fall when air resistance is not negligible?
Air resistance will increase as the velocity of the object increases and will eventually be equal to the weight of the object. This means the object will fall with constant velocity: terminal velocity
How long does it take for an object an max height to get back to original height?
The same time it took to get to max height
At what launch angle is an object going to have the greatest horizontal and vertical displacement?
45 degrees
What are free body diagrams?
Representations of the forces acting on an object
When does translational equilibrium occur?
In the absence of any net forces acting on an object
What is the velocity of an object in translational equilibrium?
Constant
Can an object in translational equilibrium also be in rotational equilibrium?
Yes
When does rotational equilibrium occur?
In the absence of any net torques on an object
What is the angular velocity of an object in rotational equilibrium?
Constant
What is angular velocity?
The rate of change of angular position of a rotating body
What is torque?
Moment of force created by the application of force at a distance from the fixed pivot point of an object in rotational motion
It is a measure of how much a force acting on an object causes that object to rotate
On the MCAT, what is the angular velocity usually when an object is in rotational equilibrium?
0
If there is no acceleretation…
There is no net force on the object
What is the lever arm?
The distance between the applied force on an object in rotational motion and the fixed pivot point
What is the fixed pivot point of an object in rotational motion called?
The fulcrum
Is a torque generating clockwise rotation negative or positive?
Negative
Is a torque generating counterclockwise rotation negative or positive?
Positive
Where does centrifugal force point?
Anti-parallel to the centripetal force
How to convert between cubic units?
Raise the usual factor by ^3
Ex: 1 m^3 = (10^2)^3 cm^3 = 10^6 cm^3
How to convert between liters and m^3?
1 m^3 = 10^3 L
1 L = 10^-3 m^3
How to convert eV to Joules?
1 eV = 1.6 x 10^-19 J
What does 1 eV represent?
the amount of energy gained (or lost) by the charge of a single electron (1.6×10^−19 Coulomb) moved across an electric potential difference of one Volt.
What do to if asked what a graph between 2 units looks like?
Look at the differences between one unit and the differences between the others over time (can also graph it)
- log A/B = ?
= log B/A
