Physics 2019 Sydney BOys (1 Viewer)

[Interdice]

 

[Interdice]

I'm confused with this.

the weight force(mg) is going down. where as the centripical force is going towards the centre

so shouldn't the expression be

3040sin(15) = 9.8m

???

 

[howcanibesmarter]

For uniform circular motion on a banked track, using a force diagram gives you:

Fc=mgsintheta
They gave you Fc, so rearranging for m is

m=Fc/(gsin15)

 

[Interdice]

I think I need to read teh textbook on this part of the syllabus. And ask teacher. Thnaks

 

[liamkk112]

shouldn't it be tan theta or is it small angle approx

 

[wizzkids]

shouldn't it be tan theta or is it small angle approx

Yes, it should be tan θ.
I disagree with that equation given in the sample answer. The result is correct, but the equation is wrong.
Here is the free body diagram of the car. The car is subjected to just two forces, they are W the force of gravity and F_N the normal force from the road. The net force is unbalanced, and this creates F_c the centripetal force that keeps the car in circular motion, even when the road has no sideways friction.

 

[Interdice]

shouldn't it be tan theta or is it small angle approx

In retrospect the question was retarded.