Circular Motion and Its Characteristics

An engine is moving on a c1rcular path of radius 200 m with speed of 15 m/s. What will be the frequency heard by an observer who is at rest at the centre of the circular path, when engine blows the whistle with frequency 250 Hz?

Choose the correct option.

Consider the following cases:

(P) A planet revolving in an elliptical orbit.
(Q) A planet revolving in a circular orbit.

Principle of conservation of angular momentum comes in force in which of these?

A stone of mass m tied to a string of length l is rotated in a circle with the other end of the string as the centre. The speed of the stone is v. If the string breaks, the stone will move 

Angular displacement (θ) of a flywheel varies with time as θ = at + bt² + ct³ then angular acceleration is given by ____________.

Assume that the earth goes round the sun in a circular orbit with a constant speed of 30 kms

If a cyclist doubles his speed while negotiating a curve, how does the tendency to overturn vary? 

A car of mass M is moving on a horizontal circular path of radius r. At an instant its speed is v and is increasing at a rate a. 
(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 $$\frac{{\text{mv}}^2}{\text{r}}$$

(c) The friction coefficient between the ground and the car is not less than a/g.
(d) The friction coefficient between the ground and the car is $$\mu ={\tan }^{-1}\frac{{\text{v}}^2}{\text{rg}.}$$