Circular Motion question (1 Viewer)

[sean182]

hey can someone please help me answer this?

Assess the following statement about a car moving at a constant speed around a roundabout:
"There is no net force acting on the car because the speed is constant and the frictional force between the tires and the road balances the centripetal force on the car"

has this got to do with the fact that velocity is always changing in circular motion, and how do i word it? thanks!

 

[Affinity]

"the statement is wrong because the car's velocity is changing, hence implying a net force is acting on it"
supplement with BS about the difference between velocity and speed, newton's 2nd law (or was it 3rd) F=ma to fill in all the lines provided

ridiculous way to ask a question about physics though.

 

[jyu]

hey can someone please help me answer this?

Assess the following statement about a car moving at a constant speed around a roundabout:
"There is no net force acting on the car because the speed is constant and the frictional force between the tires and the road balances the centripetal force on the car"

has this got to do with the fact that velocity is always changing in circular motion, and how do i word it? thanks!

There is a net force acting on the car because the velocity is changing continuously as the car moves in a circle at constant speed. Changing velocity means acceleration and a net force is required according to Newton's second law. For constant speed the net force is always towards the centre of the circle and hence it is called centripetal force. The source of this net force (centripetal force) is the friction between the tyres and the road. The road exerts this friction force on the tyres (car) towards the centre of the circle, resulting in the centripetal acceleration of the car. Without friction the car cannot make the turn.

:wave:

 

[sean182]

thanks