Term
What is the most important noncontact force? 

Definition


Term
What is Newton's Law of Gravitation state and what is the formula? 

Definition
It describes the concept of gravity. Any two particles attract one another with a force directly proportional to the product of their masses and inversely proportinal to the square of their distances between center of mass
F = (G x m1 x m2) / r^2 


Term
What is weight? And what is the equation? And units? 

Definition
It is a vector quantity and it is the attractive force of the earth on an object
W = mg (newtons), where g = 9.81m/s^2 


Term
What are the units of mass? 

Definition
it is a scalar quantity and it is kg 


Term
What is the effect produced by gravity? 

Definition


Term
Is the acceleration due to gravity the same everywhere on the earth's surface? 

Definition
No, because the points on the earth are not equidistant from its center! Not perfect spherical 


Term
Through what point does the resultant force act on a body? 

Definition
Through the center of gravity (CG). Does not always have to be within the physical limits of the body 


Term
What are the forces that influence a projectile's flight? 

Definition
Gravity (vertical only) and Air resistance (always opposes motion, we will use negligible air resistance) 


Term
What are the (3) factors we control to manipulate flight trajectory? 

Definition
Speed of release, and height of release, and angle of release, 


Term
What is the point in time at which an object is considered a projectile? And what is the flight path of a projectile called? 

Definition
The instant of release. It's called a trajectory. This type of motion has no external forces acting on it except for gravity and air 


Term
Without air resistnace, a projectile's flight path is called what? And what is the highest point called? 

Definition


Term
what happens to d(horizontal) in each of these cases: speed increase.. dh ..? heigh increase.. dh ..? 

Definition
speed increase.. dh ..increases height increase.. dh ..increases, because vh is the same BUT t(tot) increases because the object has farther to fall 


Term
How do we know if motion is angular? 

Definition
If 2 pts on the same body move different distances in a given time 


Term
if h=0, what is the optimal angle of release for a projectile? 

Definition
45 degrees. 30 degrees and 60 degrees will have a shorter horizontal distance 


Term
If speed is held constant, what happens to the optimal angle as you increase the height? 

Definition
the optimal angle decreases AWAY from 45 degrees 


Term
If height is held constant, increasing the speed of release results in what for the optimum angle? 

Definition
getting closer to 45 degrees 


Term
to which factor is d(horizontal) most sensitive to? 

Definition


Term
What is a very important feature of human motion? 

Definition
Segment rotations combine to produce linear motion of the whole body 


Term
Key concept: motion of any point on a rotating body can be described in linear terms. What info is required? 

Definition
1. axis of rotation 2. location of point of interest relative to axis 


Term
What are the units for angular velocity? What are the units if you are using angular velocity in an equation? 

Definition
degrees/s but if you are using it in an equation it must be in radians/second! 


Term
what is the formula for linear and angular displacement? and what units? 

Definition
d=(theta)(r) where d is the linear dist the point of interest has traveled theta is the angular dist and r is the linear distance that the point of interest is located from the axis
theta MUST be expressed in radians!!!!!!!!! 


Term
what is the formula for linear and angular velocity? 

Definition
V(tangential)=w x r w  angular velocity in rad/s!!! r  radius of rotation of point of interest 


Term
how do you convert from degrees to radians? 

Definition
divide the degrees by 57.3 to get radians multiply the radians by 57.3 to get degrees 


Term
what are you doing if you are maximizing v(tangential)? aand how do you do it? 

Definition
you are maximizing the linear velocity of a point located distally on a rotating body maximize vt by... increase w increase r increase both 


Term
why is it difficult for an athlete to maintain w if r is increased, vice versa? 

Definition
moment of inertia think of a sledge hammer 


Term
What happens during linear and angular acceleration, what is the object forced to do? 

Definition
Follow a curved path due to inertia. The continuous change in direction represents change in direction of velocity i.e. acceleration! 


Term
what is centripetal acceleration? 

Definition
the linear acceleration that describes the change in the DIRECTION of v(tangential) of an object foloowing a curved path (aka radial acceleration) 


Term
what is tangential acceleration? 

Definition
a(t)  the linear acceleratoin that describes the rate of change in MAGNITUDE of tangential velocity 


Term
give an example of centripetal acceleration and its effects 

Definition
as a hammer thrower spins just before release, the hammer follows a curved path. at release, there is no more centripetal force and the hammer takes off along a tangent line 


Term
explain the physics of a sprinter running a curve 

Definition
they are continual undergoing a change in direction, i.e. there is an a(centripetal). 


Term
for all rotational and curvilinear motions, resultant acceleration = 

Definition
the vector sum of the centripetal and tangential accelerations 


Term
what is the formula for centripetal acceleration? and what happens if you change some of the variables? 

Definition
a(c)=[v(t)^2]*r = (w^2)*r if you increase v(t), higher force is needed to maintain curved path (produce ac) if you decrease r (radius), results in higher ac, also need greater force to maintain curved path 


Term
what is the advantage of banked turns? 

Definition
banking faciltates development of centripetal force, so less dependent on friction as a source of centripetal force 

