The body of a bus begins to rattle something, when the bus picks up a certain speed, why?

A bus A travelling at a speed of 70 km/h just overtakes another bus B at a speed of 60km/h. The length of each bus is 10m. Calculate the time taken by the bus A to overtake bus B.

The de-Broglie wavelength of a bus moving with speed v is lambda . Some passengers left the bus at a stopage. Now, when the bus moves with twice its initial speed, its kinetic energy is found to be twice its initial value. What will be the de-Broglie wavelength, now?

Why does a person in a bus tends to fall forward when it stops suddenly?

What is the state of a person sitting in a moving bus w.r.t. a person standing at the bus stand and why?

A bus travels 700 km at a certain speed. If the bus driver reduces the speed of bus to 20 km/h then the bus will take four hours more to travel the same distance. Then find the initial speed of the bus ?

(a) What happens to the passengers travelling in the bus when the bus takes a sharp turn ? Give reasons for your answer. (b) Why are road accidennts at high speeds very much worse than road accidents at low speeds ?