A boat is being towed at a speed of 20 m per second.The tension in the towling is 6KN.Calculate the power suppiled to boat.

Two organ pipes one open at both ends,and the other open at one end only give their fundamental noteswhose frequencies differ by 25 vibration per second.The length of the open pipre is 96 cm.Calculate the length of the closed pipe if the velocity of sound in air is 330 m(s)^-1 .

A stone is dropped from a rising balloon at a height of 75 m above the ground. It reaches the ground in 6 seconds. Calculate the velocity of the balloon just at the moment when the stone is dropped.

A string 25 cm long and having a mass of 2.5 g is under tension.When the string is vibrating in its first overtone and air in a 40 cm long closed pipe in its fundamental frequency 8 beats per second are heard.it is observed that decreasing the tension in the string decreases the beat frequency.Find the tension in the string.[Velocity of sound is 320 m/s]

A steel has a radius of 10mm and a length of 1.0m. A 100kN force stretches it along its length. Calculate stress and strain on the rod. Young's modulus of steel is 2.0 xx 10^11 Nm^-2 .

A paricle is projected with a velocity of 40ms_-1 . After two seconds, it crosses a vertical pole of height 20.4m. Calculate the angle of projection.

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 man in a boat moving away from a light house 100m high takes 2 minutes to change the angle of elevation of the top of light house from 60° to 30°,find the speed of the boat.

A pump extracts water from 50m depth and ejects per sec 10 kg water with a velocity of 10m/s.Calculate is power.

The displacement y of a particle in a medium can be expressed as y =10^(-6) wSin(100t+20x), where t and x are in second and metre respectively. Calculate the speed of the wave.