Originally posted by Best101 I need some help with some formulas. Can someone tell me the formulas for finding Angular Velocity, and Tangental(SP?) Velocity?
These are for Circular Motion problems
Angular velocity and tangential velocity sometimes got confusing.
Ang v is the actual speed you go around the circle; tangential speed is the speed you are going tangential to the circle - for example if you swing a rock and let go, it flies off in a straight line TANGENTIAL to the circle with a tangential velocity.
A 40 kg child takes a ride on a ferris wheel that rotates 4 times / minute and has a radius of 8 m. (A) what is the centripetal acceleration of the child?
Ca = v^2 / r
- you know r
- you need to find the angular velocity: 4 revs/ 60 secs(in a minute) * (2 * pi * 9) (Circumference) = v.
(B) what force does the seat exert on the child at the lowest point of the ride?
Fnet = Fc + Fn. Note that the seat exerts a normal force upward. Fn is equal to mg. Fc is the center seeking force , m(v^2/r).
Fnet = m(v^2/r) + mg
Fnet = 40(v^2 / 9) + (40)(9.8) and solve (you figure v in part a).
(C)What force does the seat exert on the child at the highest point of the ride.
Fnet = mg - Fc (the normal force is now opposite of cf so they subtract...remember Fn = mg).
(D) what force does the seat exert on the child halfway between the top and bottom of the circle.
Now, Fc is pointing to the right towards the center while Fn is still pointing up, forming a right triangle. You must use pythagorean to find the resultant.
Originally posted by Ramned Angular velocity and tangential velocity sometimes got confusing.
Ang v is the actual speed you go around the circle; tangential speed is the speed you are going tangential to the circle - for example if you swing a rock and let go, it flies off in a straight line TANGENTIAL to the circle with a tangential velocity.
Angular velocity is measured in degrees or radians per unit of time; tangential velocity is distance per time.
An object's tangential velocity IS its velocity, which being a vector quantity is constantly changing. When the string breaks on that rock you are swinging around your head it flies off with that velocity.
Originally posted by Best101 I need some help with some formulas. Can someone tell me the formulas for finding Angular Velocity, and Tangental(SP?) Velocity?
Originally posted by wolfgang59 An object's tangential velocity IS its velocity, which being a vector quantity is constantly changing. When the string breaks on that rock you are swinging around your head it flies off with that velocity.
tangential velocity is a vector quantity, but since its direction is always tangent to its position in the circular path it travels, is it at all useful to consider tangential speed (the magnitude of tangential velocity)? i'm not much of a physics guy, just sort of mathematically musing...
Anyone good in Physics?
08 Dec '07 02:45
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