Javier colindres (yes I will do 30 by myself) Flashcards
(30 cards)
Which factor affects the force of gravity between objects?
Distance
and
Mass
Circular Motion
motion with constant radius of curvature caused by acceleration being perpendicular to velocity
Rotational Speed
the speed with which an object moves through an angle for every unit of time; units: RPM (revolutions per minute), rad/s, θ/s
Formula for Centripetal Acceleration
a = v^2/r = 4rπ^2/T
where v = velocity, r = radius, T = period
Formula for Centripetal Force
F = ma = m(v^2/r)
where m = mass, a = centripetal acceleration, v = velocity, r = radius
Formula for Torque
Torque = r x F
where r = the displacement vector, F = the force vector
If a feather and a hammer are dropped at the same time on the moon, where there is no atmosphere, which one will hit the ground first?
both will hit at the same time
Why does a ball at ground level move downwards?
Gravity pulls the ball toward the ground
A ball on Earth is 1 kg. What is the gravitational force acting on that Ball? (F=mg) (Gravity = 9.8)
9.8 N
Angular Momentum
the quantity of rotation of a body, which is the product of its moment of inertia and its angular velocity
Work
release of Energy in moving an object, force exerted thru a distance w=Fd in Joules
Energy
the ability to do work
Potential Energy
Stored energy, PE=mg (change in) h in Joules
Formula for Rotational Inertia
I = mr^2
where m = mass, r = distance, I = rotational inertia
Formula for Angular Momentum
L = Iω where L (angular momentum) translates to linear momentum (p), and I (moment of inertia) translates to mass (m), and ω (angular velocity) translates to velocity (v). This is the translation from rotational (circular world) terms to linear terms (linear world).
Period
the amount of time it takes to complete one cycle (1 revolution)
Centripetal Acceleration
Newton’s First Law states that a body in motion stays in motion at a constant speed and in a straight line unless acted upon by a net force; therefore, a force must be pulling inward on an object moving in a circular path in order to prevent it from moving in a straight path.
Centripetal (“Center-Seeking”) Force
any force that acts at a right angle to a moving object’s path and results in circular motion
Centrifugal (“Center-Fleeing”) Force
This force is not an actual force; it is a fictitious force that seems to pull outwards on an object on a circular path. This effect is due to inertia, or the tendency for a moving object to follow a straight path.
Simulated Gravity
Centrifugal force can simulate gravity because from within a rotating frame of reference, there seems to be a centrifugal force directed outward.
Two kinds of Mechanical Energy?
Potential and Kinetic
What must remain constant in a system?
total amount of energy
what is PEs formula?
1/2kx^2
Can work be positive or negative?
Yes. Work is a scalar quantity and can be positive or negative. Work is positive when the component of force is in the same direction as the displacement, like when you lift a box. Work is negative when the force is in the direction opposite the displacement.
