Term
Uniform Circulation Motion def 

Definition
motion in a circle of a constant radius at a constant speed 


Term
In uniform circular motion, instaneous velocity is always ____ to the circle 

Definition


Term
give the formula for the acclertaion in uniform circular motion 

Definition
a_{R= v2}
r
unit: m/s^{2} 


Term
For an object to be in uniform circulation there must be ______ 

Definition
a net force acting on it
ex. like swinging a ball on a string 


Term
The accleration in uniform circular motion is called____ or ____ accleration and it points__________ of the circle 

Definition
centripetal or radial accleration,
towards center 


Term
If the centrigufal force vanishes the object will fly ____ to the circle instead of _____ 

Definition
off tangent, outward
the natural tendency of the object to move in a circle must be overcome 


Term
express the acceleration in uniform circualr motion in terms of force 

Definition
ΣF_{R= }ma_{R}= m v^{2}
r
recall that sum of net force= accleration x mass 


Term
Describe how a car travels along a curve, what forces are acting?
If the roads is flat? 

Definition
there must be a net force towards the center of the actual curve (which is arc shaped ∩)
b. If the road is flat the force is friction 


Term
Highway Curves, Banked & Unbanked:
If the frictional force is insufficent the car will tend to move in a ____ 

Definition


Term
The Clothoid Loop
The radius at the bottom is significantly (smaller/bigger) than the radius at the top of the clothoid loop 

Definition


Term
Highway Curves, Banked, and Unbanked
___________ the curve can help cars from skidding 

Definition


Term
Describe how banked highway curves works. 

Definition
There is ONE speed in which the :
entire centripetal force is supplied by the HORIZONTAL (x)component of the NORMAL force
NO friction is required!



Term
Give the formulas that make banking of highway curves possible.


Definition
(x) F_{N} cos Ө = mg
(y) F_{N} sin Ө =ma_{c }= (mg ) sin Ө
(cosӨ)
= (m’s will cancel)
= (g/cosӨ) sin Ө = v^{2} /r
(recall sin/cos = tan)
= g tan Ө = v^{2} /r
Final Equation:
V=√gr tan Ө



Term
Newton's Law of Universal Gravitation
If the force of gravity is being excerted on objects on Earth, what is the origin of the force? 

Definition
this force comes from the Earth, this force also keeps the Moon in its orbit. 


Term
What 2 factors influence the gravitional force & why? 

Definition
 the gravitional force is proportional to both masses involved
(aka the Earth excerts a downward force on you & you excert an upward force on Earth b/c these masses are very opposite the rxn is small & negliable , however the rxn force btwn the Earth & moon is SIGNIFICANT)
 the gravitional force decreases as the distance btwn the two masses increases (distance is measured from the center of both of the masses being considered)
 (which can be represented by radius squared)



Term
Write the formula for Law of Universal Gravitation 

Definition
F= G m_{1}m_{2}
r^{2}
where G=6.67 x 10^{11 }N^{•}m/kg^{2}
r= distance btwn objects
m1= object/planet staying still
m2= one that is moving 


Term

Definition


Term
Satellites & Weightlessness
How do satellites work? 

Definition
the tangential speed:
 must be HIGH enough so that satellite does not return to Earth
 but not too high that it escapes Earth's gravitional pull



Term
The satellite is kept in orbit by its ____ 

Definition
speed, it is continually falling, but the Earth curvees from Earth underneath it. 


Term
T or F: Objects in orbit do not have a gravitional force acting on them. 

Definition
False, alhough objects in orbit are said to experience a gravitational force,there is still a gravitional force.
 The satellite & all of its components are in FREE FALL= no normal force
 (thats where the feeling of weightlessness comes from)



Term
What is apparent weightlessness 

Definition
 Just like the:
 satellite & all of its components are in FREE FALL= no normal force
 (thats where the feeling of weightlessness comes from)



Term

Definition


Term
Keplers First Law:
The orbit of each is 

Definition
an ellipse, with the sun at one focus 


Term
Kepler's 2nd Law:
an imaginary line____... 

Definition
drawn from each planet to the Sun sweeps out equal areas in equal times. 


Term
Kepler's 3rd Law: relate the orbit & orbital law 

Definition
the period^{2} of the orbit for all objects orbiting the same planet/star
depends on
orbital distance^{3}



Term
Give formula for Kepler's 3rd law
that relates M, r,G, T^{2} 

Definition
(4∏^{2}/GM)• r^{3 }= T^{2}
where T^{2} = the period squared for all objects orbiting the same planet/star
G= 6.67 x 10^{11}
r^{3} = orbital distance cubed
M= mass of planet staying still
*note :memorze this formula b/c it can switched around to solve for other variables for example if you want to find the mass of a planet knowing how far it is from Earth



Term
The greater the speed v, then ____
&
The greater the radius then______ 

Definition
the higher the speed:
the FASTER the velocity changes direction
the higher the radius:
the LESS rapidly the velocity changes direction 


Term

Definition


Term

Definition
# of revolutions per second 


Term
period is represented by what letter? 

Definition


Term

Definition
time required for 1 complete revolution 


Term
Give the equation that relates period + frequency 

Definition


Term
Give the equation for an object revolving in a circle (of circumference 2πr), at a constant speed v 

Definition
v= 2πr
T
This is true because when an object travels 1 circumference it also traveled one revolution. 


Term
newtons gravitational force formula:
F=G m1m2/r2
unit for distance 

Definition


Term
newtons gravitational force formula:
F=G m1m2/r2
unit for mass 

Definition


Term
newtons gravitational force formula:
F=G m1m2/r2
unit for answer 

Definition


Term
Give formula for Kepler's 3rd law
that relates the period (T) and the orbital radius (r) for two planets 

Definition
(T_{1}/T_{2 })^{2 }= (r_{1 }/ r_{2} )^{3}
* use this formula when you want to determine the distance of planet (r) from anothe planet, knowing its period (T). 


Term

Definition

