Circular motion (1 Viewer)

[ramanij]

What was required for the car going around the roundaabout? and was the observer correct or wrong?

 

[jiegu]

i think this question need to talk about the velocity is constant

 

[Kelvy]

I thought velocity wasn't constant :S As although the magnitude of velocity is constant, the direction varies.......

 

[grimreaper]

no you had to say that it was actually the friction providing the centripedal force - there was a net force

 

[The Bograt]

Shit I said that the velocity was not constant since the car was changing direction, but the speed was constant. I said that the friction created a net force since it contributed to the centrepedal motion, in that it was like the tension force. This force acted horizontally to the car and directed towards the centre of the roundabout.
What do you guys think?

EDIT: I'm with you Kelvy, I thought the velocity was changing

 

[kris12345]

yeah i equated the force of the car on the road and said that if the force was to cancel each other the centripical force must equal the force on the road
but it didnt so there was still a net force

 

[nerdboy]

i reckon bograts right

 

[Kelvy]

I said there is a net force - the friction provides the centripetal force!

Omg i love 4u maths, it helped me so much for that.......i just kinda imagined a banked track but the angle to the horizontal was 0

 

[kris12345]

yeah i think he may be cause the question ask for in relation to the horizontal forces

 

[budj]

I said that the frictional force always upposes the direction of motion, and this is the tangential velocity, but this is acting perpendicularly to the centripetal force, therefore having no component in its direction. Hence th statement was incorrect

 

[Jezzabelle]

I said that the frictional force always upposes the direction of motion, and this is the tangential velocity, but this is acting perpendicularly to the centripetal force, therefore having no component in its direction. Hence th statement was incorrect

hmm i talked about the fact that the net force cos the car was going in centripetal motion and so was under the force of acceleration towards the centre of the circle... friction just keeps it on the road, the acceleration force keeps it in a circle?

 

[Plebeian]

I thought: Friction between the car and the road provides a centripetal force. The car does undergo a net force because it is moving in a circle - ie. it has changing velocity and thus acceleration. If there was no net force acting on it, it would fly off the road. The statement is wrong because (1) it said the centripetal force balanced the friction (they are the same) and (2) there is a net force acting.

 

[Shuter]

I got something like there was a force of at least 2858.5 N or something around that, required to keep the car from wanting to continue in a strait line (Newtons law).

 

[ShaunSmith]

F=mv^2/r
or something isnt it?
was acceleration and therefore a net force that does not equal 0.
i liked that question, dont ruin it by saying i was wrong! thanks!

 

[gordo]

u have gravity pushing the car into the road, the normal pushing it back up
and u have the friction of the car tyres = mv^2 / r
plus u have the car's thurst to counter air resistance and friction to keep it at a constant velocity
wat they said in the statement was that centripital force was balanced by the friction of tyres, the friction of tyres IS the centripital force, balancing the thrust of the car, otherwise it would fly off on a tangent, pretend the tyres were ice cubes for example

 

[boz]

go 4 u, would have had no idea about net forces otherwise. i also said something about there is a changing velocicity and therefore there is a net force, and the force connot = zero. as well as calcs and crap, thats right i craped on the page.

 

[Maiwand]

is this right? i said mv2/r = ma and found out accelerationg was 3 or some shit and if the accelration was any different a net force would occur? i dunno i stuffed dat question up hardcore