WORK,GRAVITY, VERTICAL AND HORIZONTAL CIRCULAR MOTION Flashcards
What is work ?
The product of force and displacement
W=Fs
F and s must be in the same dimension
work is done by……
something onto something
The Basics of circular motion
in Circular motion where is the acceleration directed to?
torwards the centre of the circle
what is reqiured to cause an acceleration torwards the centre of the circular path?
there must be a net force that acts towards the centre of the circular path.
In Horizontal circular motion what happens when frictional force decrease?
1.The vertical componetn of the reaction force is not affect and will continue to balance the weight force
2.The horizontal component of the reaction force is reduced because of the limited friction
Explain how angles that are in Horizontal circular motion would change as the velocity of the ride icreases.
a larger velocity requires a larger centripetal force as shown on the Fc formula,This is achieved with a larger horizontal component of the tension in the cable .Therefore the angle will increase
if friction is greater than the Centripetal Force what does this mean?
The frictional force can supply the Centripetal force causing it to follow a curve
on this formula for velocity on a banke curve ,usually for cars what happens when the velocity increases ?
1.as velocity increases ,Tan theta increases which indicates that the angle increases.
2.A faster velocity requires a larger centripetal force
what is the Centripetal Force?
The force that causes the Centripetal acceleration.
‘‘its a calculation of the force required for circular motion”
what is the centripetal force supplied by?
Friction
whats the reason ,one cannot complete circular motion hence leading to them falling ?
The friction can not supply the required centripetal force
LEANING IN CIRCULAR MOTION.(IMPORTANT)
1.The Horizontal component of the Reaction force supplied by friction supplies the required centripetal force
2.The vertical component =the weight
how to find an angle required for Centripetal force
1.Use Geometry for circles
2.utilise the triangle by using the horizontal and vertical componet
3.to get a better speed one must have a smaller angle made with the horizontal
Banked Curves (free body diagram and vector Diagram)
1.Here there is no Reaction force but the re is a NORMAL FORCE INSTEAD.
2.THE angle of the bank is equal to the top angle of the vector sum diagram
3.
When frictional forces decreases what effect will on the horizontal and vertical compenents of the reaction force acting on a leaning object
1.the vertical component wont be affected and will continue to balance the weight force
2.The Horizontal component of the reaction force is reduced because of the limited friction
How to get an angle from the conical pendulum
Diagrams for the Conical pendulum.
1.the angle on the second triangle = the angle of the second triangle
2.Tension of string = mg/cos of the angle
explain how an angle shown in a conical pendulum situatio would change as the mass of the object increases
The increase in mass will scale both sides by the same proportion.Therefore the angle won’t be affected by the change in mass
Tension in a pendulum =
mg/cos 0
HOW to get the TIME PERIOD of an objetc on a conical penduleum
For vertical cirular motion…
1.always draw a vector diagram
2.assign a direction convention(torwards the centre is positive)
3.start the problem by writing a vector sum equation
Situation 3 of vertical circular motion:at the bottom of the loop
the fater the ball the more the Centripetal force
also note on a free body diagram N>W
situation for vertical circular motion problems(At the top of a loop inside)
The slowest possible speed Fc=w
v=square root of g and r
situation 2 for vertical circular motion objects at the top of a loop(outside)
This works for Ferris wheels
Its just not a normal force that’s there
their is also tension
How to get the mass of a planet given the radius and time period do this.
1.Calculate the orbital speed which is V using 2pi r/T
2.the Equate the Fc formula to the Fg which is newtons law of Universal Gravitation .Fc=Fg
3.to get the velocity it will be v=Square root of Gm/r
4.Then you can proceed to get the mass
5.
