A cheetah is the fastest land animal and can achieve a peak velocity of `100 km//h` upto distances less than 500 m. If a cheetah spots his prey at a distance of 100 m. What is the minimum time it will take to get its prey, if the average velocity attained by it is`90 km//h`.

If a cheetah spots his prey at a distance of 100m, what is the minimum time it will take to get its prey if the average velocity attained by it is 90 km/h?

Priyanka takes 30 minutes to cover a distance 3 kilometres on a bicycle. Calculate her velocity units of kilometre/min, m/s, and km/h.

Two paper screens A and B are separated by a distance of 100m.A bullet plerces A and than B. The hole is B is 10 cm below the hole in A.If teh bullet is travelling horizontally at the time of hitting A,then what is the velocity of the bullet at A?

A motor car moving at a speed of 72 km /h can not come to a stop in less than 3.0 s while for a truch this time interval is 5.0s On a highway the car is behind the truck both moving at 72 km /h The truck geives a signal that it is going to stop at emergency. At what distance the car should be from the truck so that it does bot bump onto (collide with) the truck. Human responde time id 0.5 s. (comment : This is to illustrate why vehicles carr the message on the rear side. "Keep safe Distance").

classically an electron can be in any orbit around nucleus of an atom. Then what determines the typical atomic size? Why is an atom not, say, thousand times bigger than its typical size? Thequestion had greatly puzzled Bohr before he arrived at his famous model of the atom that you have learnt in the text. To simulate what he might well have done before his discovery, let us play as followswith the basic constants of nature e, me, c and see if we can get a quantity with the dimensions of length that is roughly equal to the known size of an atom (~ 10 m).- You will find that the length obtained above is many orders of magnitude smaller than the atomic dimensions. Further, it involves c. But energies of atoms are mostly in non-relativistic domain where c is not expected to play any role. This is what may have suggested Bohr to discard c and look for else h had already made its appearance elsewhere. Bohr lay in recognising that h, m_e , and e will yield the right atomic size. Construct a quantity with the dimension of length from h, me, and e and confirm that its numerical value has indeed the correct order of magnitude.