Kinematics & Dynamics Flashcards
Work and Energy
Joule (kg•m^2)/s^2
Power
Watt (kg•m^2)/s^3
Finding magnitude of vectors
V=sqrt(x^2+y^2)
Finding Torque magnitude and Direction
F•lever arm•sin(theta)=Magnitude
Direction:
I.e. Consider resultant C where C=AxB
Point thumb in direction A and extend fingers in direction B. Direction your palm face determines direction of C (For MCAT it’s usually in or out of page)
Gravitational Force
F=(Gm1m2)/r^2
Note: MCAT usually tests on proportionalities. I.e. The magnitude is inversely related to the square of distance (if r is halved, then the force is quadrupled) and directly related to the masses (is m1 is tripled then the force will triple)
Center of mass
X=(m1x1 + m2x2 + …) / m1 + m2 +…
Newtons First Law
F=ma=0
An object at rest will remain at rest unless a force is applied
Newton’s second law
F=ma
An object will accelerate when a sum of forces with a non zero resultant fore acts on it
Newton’s third law
F(ab) = -F(ab)
To every action there is an equal and opposite reaction
Kinematics (no displacement)
v= vo + at
VAT
Kinematics (no final velocity)
v= vot + 1/2at^2
TAX
Kinematics (no time)
v^2= vo^2 + 2ax
VAX
Force of gravity (Directions)
Constant (can be ignored) in horizontal direction
If it’s parallel to plane, it’s F =mgsin(theta)
If it’s perpendicular to the plane, F=mgcos(theta)
Note: be sure to add all forces in same direction for final Force of the direction. Use the sum of the X forces and sum of Y forces to find resultant (direction) of forces
Centripetal acceleration
Always points inward; can be separated into radial and tangential components in which the latter is 0 for uniform circular motion bc there’s no change in speed
Fc = (mv^2) / r
Tension
Is equal and opposite of static friction in the horizontal direction and equal and opposite of mg in vertical direction
