The time between a clap and its echo from a wall is 0.1 s. If the distance of the wall be 17.5 m, calculate the speed of sound.

In a Young's double slit experiment ,the distance between the slits and the screen is 1 m.If the distance between the slits is 5 mm,the fringe width is found to be 0.1 mm.Calculate the wavelength of the light used.

Salma takes 15 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of 2m/s, calculate the distance between her house and the school?

A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR the time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0 s. What is the distance of the enemy submarine? (Speed of sound in water = 1450 m s^-1 ).

A convex lens of power 4D is placed at a distance of 40 cm from a wall at what distance from the lens should a candle be placed so that its image is formed on the wall?

A block f mass M is held against a rough vertical wall by pressing it with a finger. If the coefficient of friction between the block and the wall is mu and the acceleration due to gravity is g. calculate the minimum force required to be applied by the finger to hold the block against the wall?

A 70 kg man stands in contact against the ineer wall of a hollow cylindrical drum of radius 3 m rotating about its vertical axis with 200 rev//min . The coeffcient of friction between the wall and his clothing is 0.15. What is the minimum rotational speed of the cylinder to enable the man of remain stuck to the wall ( without falling) when the floor ids suddenly removed?

In a Young's double slit experiment ,light has a frequency of 6 xx 10^(14) s^(-1) .The distance between the centres of adjacent brigth fringes is 0.75 mm. If the screen is 1.5m away then, find the distance between the slits.