Two towers on top of two hills are 40km apart. The line joining them passes 50m above a hill halt way between the towers. What is the longest wavelength the towers without appreciable diffraction effects?

Two towers on top of two hills are 40 km apart. The line joining them passes 50 m above a hill halfway between the towers. What is the longest wavelength of radio waves, which can be sent between the towers without appreciable diffraction effects?

Two flagstaffs stand on a horizontal plane. A and B are two points on the line joining their feet and between them. The angle of elevation of the tops of the flagstaffs as seen from A are 30^(@)and 60^(@) and as seen from B are 60^(@) and 45^(@). If AB is 30 m, the distance between the flagstaffs in metre is

The angle of elevation of the top of a tower 30m high from the foot of another tower in the same plane is 60^(@) and the angle of elevation of the top the second tower from the foot of the first tower is 30^(@) . Find the distance between the two towers and also find the height of the other tower.

The angles of elevation of the top of a tower from two points at a distance of 4m and 9m from the base of the tower and in the same straight line with it are complementary. Prove that the height of the tower is 6m.

Two small and similar bar magnets have magnetic dipole moment of 1.0 Am^(2) each. They are kept in a plane in such a way that their axes are perpendicular to each other. A line drawn through the axis of one magnet passes through the centre of other magnet. If the distance between their centers is 2 m, find the magnetic field at the mid point of the line joining their centers.

STATEMENT-1: Two balls are dropped one after the other form a tall tower. The distance between them increases linearly with time (elapsed after the second ball is dropped and before the first hits ground). STATEMENT-2: Relative acceleration is zero, whereas relative velocity non-zero in the above situation.

Two trains A and B of length 400 m each are moving on two parallel tracks with a uniform speed of 72 km h^(-1) in the same direction, with A ahead of B. The dirver of B decides to overtake A and accelerates by 1 ms^(-2) . If after 50s, the guard of B just brushed past the driver of A, what was the original distance between them ?

Two trains A and B of length 400 m each are moving on two parallel tracks with a uniform speed of 72 km h^(-1) in the same direction, with A ahead of B. The driver of B decides to overtake A and accelerates by 1 m s^(-2) . If after 50 s, the guard of B just brushes past the driver of A, what was the original distance between them ?

Two particles of mass m_(1) and m_(2) are projected from the top of a tower. The particle m_(1) is projected vertically downward with speed u and m_(2) is projected horizontally with same speed. Find acceleration of CM of system of particles by neglecting the effect of air resistance.