A train is moving east ward at 10 m `s^-1`. A waiter is walking eastward at 1.2 m `s^-1` and a fly is charging towards the north across the waiter's tray at 2 `m//s`. What is the velocity of the fly relative to the earth.

A scooter going towards east at 10 m s^-1 turns right through an angle of 90^@ . If the speed of the scooter remains unchanged in taking tum, the change in the velocity of the scooter is

A particle moves for 20 s with velocity 3 m//s and then moves with velocity 4 m//s for another 20 s and finally moves with velocity 5 m//s for next 20 s. What is the average velocity of the particle ?

What is the de Broglie wavelength of a 2 kg mass moving with a velocity of 10 m/s?

A body covers one-half of its journey at 40 m s^-1 and the next half at 50 m s^-1 . Its average velocity is

A 150 m long trains travelling from east to west at a speed of 20 m/s. A bird is flying from west lo cast at a speed of 5 m/s. How long will the bird take to cross the train?

Velocities of three molecules are 2,3 and 4 m/s. Ratio of mean velocity to R.M.S velocity is

A body covers one-half of its journey at 40 m s^-1 and the next half at 50 m s^-1 . Its average velocity is.

A kite is moving horizontally at a height of 151.5 m . If the speed of the kite is 10 m/s , how fast is the string being let out, when the kite is 250 m away from the boy who is flying the kite? The height of the boy is 1.5 m. (A) 8 m/s (B) 12 m/s (C) 16 m/s (D) 19 m/s

A train is moving with a uniform speed of 33 m//s and an observer is approaching the train with the same speed. If the train blows a whistle of frequency 1000 Hz and the velocity of sound is 333 m//s then the apparent frequency of the sound that the observer hears is