Chapter 6: Uniform Circular Motion and Gravitation Flashcards
Define angular velocity
the rate of change of the angle with which an object moves on a circular path
Symbol: ω
Define arc length
Δs, the distance traveled by an object along a circular path
Define banked curve
the curve in a road that is sloping in a manner that helps a vehicle negotiate the curve
Define center of mass (com)
the point where the entire mass of an object or of a system of objects can be thought to be concentrated
Define centrifugal force
a fictitious force that tends to throw an object off when the object is rotating in a non-inertial frame of reference
Define centripetal acceleration
the acceleration of an object moving in a circle, directed toward the center
Define centripetal force
any net force causing uniform circular motion
Define coriolis force
the fictitious force causing the apparent deflection of moving objects when viewed in a rotating frame of reference
Define fictitious force
a force having no physical origin
Define gravitational constant, G
a proportionality factor used in the equation for Newton’s universal law of gravitation; it is a universal constant—that is, it is thought to be the same everywhere in the universe
Define ideal angle
the angle at which a car can turn safely on a steep curve, which is in proportion to the ideal speed
Define ideal banking
the sloping of a curve in a road, where the angle of the slope allows the vehicle to negotiate the curve at a certain speed without the aid of friction between the tires and the road; the net external force on the vehicle equals the horizontal centripetal force in the absence of friction
Define ideal speed
the maximum safe speed at which a vehicle can turn on a curve without the aid of friction between the tire and the road
Define microgravity
an environment in which the apparent net acceleration of a body is small compared with that produced by Earth at its surface
define Newton’s Universal law of gravitation
every particle in the universe attracts every other particle with a force along a line joining them; the force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them
Define non-inertial frame of reference
an accelerated frame of reference
Define radians
A unit of angle measurement
Define radius of curvature
Radius of a circular path
Define rotation angle in words
the ratio of the arc length to the radius of curvature on a circular path
What is the rotation angle equation?
Δθ=Δs/r
Δθ = change in angle
Δs = change in arc length
r = radius
Define ultracentrifuge
a centrifuge optimized for spinning a rotor at very high speeds
Define uniform circular motion.
the motion of an object in a circular path at a constant speed
A pilot can withstand an acceleration of up to 9g, about 88m/s^2 before blacking out. What is the acceleration experience by a pilot flying in a circle of constant radius at a constant speed of 525 m/s if the radius is 2820 m?
98 m/s^2 (yes the pilot blacks out)
Explanation:
I. Assess what you have: radius, and velocity
II. Asses what you need: Centripetal acceleration
III. Find a fitting equation: a_c = v^2 / r
IV: Plug in the numbers: a_c = 525m/s^2 / 2820 m
V. Solve: 98m/s^2
What is the equation for centripetal acceleration?
a_c = v^2 / r
a_c = centripetal acceleration (using _ to represent subscript)
v = velocity
r= radius
