A car of mass M is moving on a horizontal circular path of radius r. At an instant its speed is u and is increasing at a rate α.
(a) The acceleration of the car is towards the centre of the path.
(b) The magnitude of the frictional force on the car is greater than mv2/r
(c) The friction coefficient between the ground and the car is not less than α/g.
(d) The friction coefficient between the ground and the car is μ = tan -1v2/rg