WORK,GRAVITY, VERTICAL AND HORIZONTAL CIRCULAR MOTION

Question 1

What is work ?

Answer 1

The product of force and displacement

W=Fs

F and s must be in the same dimension

Question 2

work is done by……

Answer 2

something onto something

Question 3

The Basics of circular motion

Answer 3

Question 4

in Circular motion where is the acceleration directed to?

Answer 4

torwards the centre of the circle

Question 5

what is reqiured to cause an acceleration torwards the centre of the circular path?

Answer 5

there must be a net force that acts towards the centre of the circular path.

Question 6

In Horizontal circular motion what happens when frictional force decrease?

Answer 6

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

Question 7

Explain how angles that are in Horizontal circular motion would change as the velocity of the ride icreases.

Answer 7

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

Question 8

if friction is greater than the Centripetal Force what does this mean?

Answer 8

The frictional force can supply the Centripetal force causing it to follow a curve

Question 9

on this formula for velocity on a banke curve ,usually for cars what happens when the velocity increases ?

Answer 9

1.as velocity increases ,Tan theta increases which indicates that the angle increases.
2.A faster velocity requires a larger centripetal force

Question 10

what is the Centripetal Force?

Answer 10

The force that causes the Centripetal acceleration.
‘‘its a calculation of the force required for circular motion”

Question 11

what is the centripetal force supplied by?

Answer 11

Friction

Question 12

whats the reason ,one cannot complete circular motion hence leading to them falling ?

Answer 12

The friction can not supply the required centripetal force

Question 13

LEANING IN CIRCULAR MOTION.(IMPORTANT)

Answer 13

1.The Horizontal component of the Reaction force supplied by friction supplies the required centripetal force
2.The vertical component =the weight

Question 14

how to find an angle required for Centripetal force

Answer 14

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

Question 15

Banked Curves (free body diagram and vector Diagram)

Answer 15

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.

Question 16

When frictional forces decreases what effect will on the horizontal and vertical compenents of the reaction force acting on a leaning object

Answer 16

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

Question 17

How to get an angle from the conical pendulum

Answer 17

Question 18

Diagrams for the Conical pendulum.

Answer 18

note there are two triangles in the Horizontal circular motion of a conical pendulum

1.the angle on the second triangle = the angle of the second triangle
2.Tension of string = mg/cos of the angle

Question 19

explain how an angle shown in a conical pendulum situatio would change as the mass of the object increases

Answer 19

The increase in mass will scale both sides by the same proportion.Therefore the angle won’t be affected by the change in mass

Question 20

Tension in a pendulum =

Answer 20

mg/cos 0

Question 21

HOW to get the TIME PERIOD of an objetc on a conical penduleum

Answer 21

Question 22

For vertical cirular motion…

Answer 22

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

Question 23

Situation 3 of vertical circular motion:at the bottom of the loop

Answer 23

the magnitude of the normal force is Larger than the weight.This gives the sensation of feeling heavier at the bottom of a vertical circle

the fater the ball the more the Centripetal force
also note on a free body diagram N>W

Question 23

Answer 23

Question 24

situation for vertical circular motion problems(At the top of a loop inside)

Answer 24

1. weight and the normal force both assist in producing the centripetal Force 2. If the weight force is LARGER than the centripetal force then the object will fall away from the circular path

The slowest possible speed Fc=w
v=square root of g and r

Question 24

situation 2 for vertical circular motion objects at the top of a loop(outside)

Answer 24

1.the magnitude of the normal force is smaller than the weight This gives the sensation of feeling lighter at the top of a vertical circle 2.If the weight force is SMALLER than the Fc then the object will fly off the circular path

This works for Ferris wheels

Question 25

Its just not a normal force that’s there

Answer 25

their is also tension

Question 26

How to get the mass of a planet given the radius and time period do this.

Answer 26

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.