Re: [Phys-l] Circus Physics

[Bernard Cleyet <bernardcleyet@redshift.com>]

On 2010, Dec 22, , at 16:12, Stefan Jeglinski wrote:

> The vector diagram (net force on the dog down the slide) is drawn 
> wrong. If you sum up the vectors shown (friction, normal force, 
> gravity), 


And:
On 2010, Dec 22, , at 16:12, Stefan Jeglinski wrote:

> Worse is the last sentence of the paragraph above the vector diagram: 
> "To find out how fast the dog will slide, we need one other piece of 
> information, his mass."
>
> This is an abjectly incorrect statement. The acceleration down the 
> slide is g(sin(theta) - mu*cos(theta)). Not only is mass not needed, 
> but the other piece of information needed is mu (and of course theta).


I'll "stick my neck out" by suggesting the mass is required to find the friction force.

bc not bothering to read the page.