Rain is falling vertically vertically with a speed of `35 ms^-1`. Wind starts blowing after sometime with a speed of `12ms^-1` in east to west direction. In which direction should a boy waiting at a bus top hold umbrella?

Rain is falling vertically with a speed of 30 m s^-1 . A woman rides a bicycle with a speed of 10 m s^-1 in the north to south direction. What is the direction in which she should hold her umbrella?

A ball thrown vertically upward with a speed of 19.6ms^-1 from the top of a tower returns to earth in 6 sec. Find the height of tower.

On a two-lane road, car A travelling with a speed of 15ms^-1 is approached by two cars B and C moving with speed 20 ms^-1 each in opposite directions. At an instant when the distance AB is equal to AC , both being 700 m, B decides to overtake A before C does. Find the minimum acceleration required by B to avoid accident.

A siren is fitted on a car going towards a vertical wall at a speed of 36 kmh^(-1) . A person standing on the ground behind the car, listeners to the siren sound coming directly from the source as well as that coming after reflection from the wall. Calculate the apparant frequencies of both the sounds. Velocity of sound 340ms^(-1) , frequency of the siren 500Hz.

An electron enters a magnetic field of 1G with a speed [2 x 10^6 ms^-1] in a perpendicular direction. Calculate its (i) radius of path and (ii) frequency of revolution.

A police van moving on a highway with speed 30 kmh^-1 fires a bullet at a theif's car speeding away in the same direction with a spped of 192 kmh^-1 . If the muzzle spped of the bullet is 150ms^-1 , at what speed does the bullet hit the thief's car?

A player throws a bail upwards with an initial speed of 29.4 m s^-1 . Choose the x = 0 m and t = 0 s to be the location and time of the bail at its highest point, vertically downward direction to be the positive direction of x-axis, and give the signs of position, velocity and acceleration of the ball during its upward, and downward motion.

A man walking briskly in, rain with speed v must slant his umbrella forward making an angle theta with the vertical. A student derives the following relation between theta and v, tantheta = v and checks that the relation has a correct limit: as v rarr 0, theta rarr -0 , as expected.. (We are assuming there is no strong wind and that the rain falls vertically for a stationary man). Do you think this relation can be correct? If not, guess the correct relation.

A man throws balls with the same speed vertically upwards one after another at an interval of 2 seconds. What should be the speed so that more than two balls are in the sky at any time? ( g = 9.8ms^-2 )

A driver of a car travelling at 52 km h^-1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h^-1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelle farther after the brakes were applied?