5.12 Out Into Space Flashcards
What is 360 degrees in radians?
2 pi
Definition of angular velocity?
Angle an object rotates through per second
What equation links linear and angular velocity?
Linear velocity =radius x angular velocity
Equation to calculate angular velocity?
Angular velocity=angle in radians/times in seconds
What does the symbol for angular velocity look like?
Omega (curly w)
What is frequency in circular motion?
Number of revolutions per second
What is the unit of frequency?
Hertz
What is the time period in circular motion?
Time taken for a revolution
What equation links period and frequnecy
f=1/T
Why is an object travelling in a circle accelerating even at constant speed?
Its velocity is changing as its direction is changing
What is the name for acceleration in a circle?
Centripetal acceleration
Where is centripetal acceleration directed?
Towards the centre of circle
What is centripetal acceleration produced by?
A centripetal force acting towards the centre of the circle
What is a gravitational field?
Region where an object will experience a non contact force
What force will an object experience if you put it in the gravitational force of another object?
Attractive
What is a uniform field? How are the field linescshown?
Field is the same every where
Lines are parralel and equally spaced
What type of field do spjerical objects have?
Radial
What can we assume about earths gravitational field close to the surface?
Uniform
What type of law is the law of gravitation?
Inverse square law
Whats the gravitational field strength definition?
Force per unit mass
Why can we assume g is constant on earth?
Uniform field if you dont go to high
What can be said about the force a mass experiences in a uniform field?
Constant
What equation can we use to model force experienced in a uniform field?
F=mg
What is potential energy proportional to in a uniform gravitational field?
Height
Whats the equation for gravitational potnetial energy?
Change in e grav=mgh
If an object is thrown up in a gravitational field how does the energy transfer?
Initial is all kinetic, transfers to potential as it gains height,stops gaining height when all kinetic transferred to potential and then reverse happens.
How are g and r related in an inverse square law?
Gravitational field is inversely proportional to radius
What can we define gravitational potnetional energy as at a given point?
Work needed to be done to move it from infinity to that point
What is gravitational potmetial?
GPE per unit mass
What are equipotentials?
Point in a field with the same gravitational potential
What can be said about the transfer of energy when travelling along an equipotential?
Energy is constant, no work is done
What are equipotenials perpendicular to ?
Field lines
What is a satellite
A smaller mass that orbits a much larger mass
Whats a geostationary sattelite?
A satellite that orbits earth once a day so appears stationary in the sky
What does the area of a g against r graph show?
Gravitational potential
What does the gradient of a GPE against r show?
Force
What is the shape of all gravitation against radius graph?
Inverse curve under the bottom right quadrant as g is negative
Why is no work done when moving along equipotentials?
Force is perpendicular to displacement so no work done as: W=FS
