MIDTERMS Flashcards
(102 cards)
It is a description of how an object moves.
Kinematics
Who discovered that motion is determined by forces?
Galileo and Newton
In the absence of a net force, an object is at ______ or moves with _______.
rest, constant velocity
What model do we use for objects on which the net force is zero?
Mechanical Equilibrium Model
A particle at rest is in equilibrium. True or False?
True
A particle moving in a _________ at constant velocity is also in ________.
straight line, equilibrium
Mathematically: a vector = 0 vector; thus Newton’s second law equation is:
Fnet = sigma Fi = 0 vector.
What is the limitation of Mechanical Equilibrium Model?
Model fails if the forces aren’t balanced.
Newton’s laws are scalar equations. True or False?
False. vector equation
In Newtonian mechanics, what is the formula for acceleration?
a = Fnet / m. The forces acting on an object determine its acceleration.
What will happen if the forces acting on object are constant?
The object moves in constant acceleration.
In constant force model, the particle accelerates in the direction of the net force. Define it mathematically.
Fnet = sigmaFi =ma
What is the limitation of constant force model?
The model fails if the forces aren’t constant.
It is an intrinsic property of an object.
Mass
An attractive, long-range force between any two objects.
Gravity
In gravity, forces are equal on magnitude but opposite in direction. True or False?
True
Newton’s Law of Gravity equation:
F_1on2 or F_2on1 = Gm1m2 / r²
What is the value of G, called the gravitational constant?
6.67x10-¹¹ N m2/kg2
Give one of the basic constants of nature.
gravitational constant
Gravity is a constant force. True or False?
False. The force gets weaker as the distance between the object increases.
gravitational force formula:
FG = GM / R²
wherein;
M is basically (m1)(m2)
The direction of the gravitational force defines what we mean by ______.
“straight down”
All objects, regardless of mass, have the same free-fall ________.
acceleration
What is the average radius of the Earth?
6.37x10⁶ m