Our dynamic universe Flashcards
what are the equations of motion used for?
Acceleration
Projectile Motion
and any other movement question
F=ma is used when?
Unbalanced forces e.g. Friction, Air resistance
Tension
How do you calculate momentum?
p=mv
How to I find resultant forces?
Trigonometry (the hypotenuse is always the resultant force)
State Newtons 3 laws of motion?
- An object will remain at a constant velocity unless acted upon by an unbalanced force.
- The acceleration of an object is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
- Every action has an equal and opposite reaction
When do I use a vector diagram
Finding forces in two directions
Finding resultant force
Finding resultant speed
(You see a slope, think triangle)
What relationships can be used to calculate work done?
Ew =Fd
Ek = 1/2mv²
Ep=mgh
define impulse?
Change in momentum
Ft = mv − mu
What is frictional force?
the unbalanced force (the difference between the other two forces
How do I calculate impulse after a collision?
calculate momentum before & after collision
take away one value from the other
plug into Ft= mv - mu
What is Power
E/t
What is the difference between t and t’
t is proper time and t’ is time from the observers frame of reference
t < t’
Difference between l and l’
l is proper length, l’ is length from an observers frame of reference
l > l’
Calculate observed frequency
fₒ =fₛ (v/v+or-vₛ)
z=
redshift
