A 50 kg girl whose leg bones are `5m^2` in area and 50 cm long falls from a height of 2 m without breaking her leg bones.If the bones can stand a stress of `10^8 Nm^(-2)`,calculate the Young's modulus for the material of bones.

A wire of length 2.0 m, diameter 1.0 mm has 50 xx 10^-3 Omega (ohm) resistance. Calculate the resistivity of the material of a wire.

A body of mass 0.8 kg is whirled uniformlyt at the end of a string 2 m long.If teh string makes 3 revolutins in 1.5 sec,calculate the tension in the string.

A cylinderical pillar is 50 cm in diameter and 3.5 m in height. Find the cost of white washing the curved surface of the pillar at the rate of Rs 12.50 per m^2 .

A truck is pulling a car out of a ditch by means of a steel cable that is 9.1 m long and has a radius of 5 mm. When the car just begins to move, the tension in the cable is 800 N. How much has the cble streched ? (Young's modulus for steel is 2xx 10^11 N m^-2) .

If a man lifts a load up with the help of rope such that it raises the load of mass 50 kg to a height of 20 m in 100 seconds. Find the power of man. (Take g = 10ms^-2 )

Two pith-balls each of mass 5xx10^-4 kg are suspended from the same point by silk threads 0.2 m long equal charges are given to the balls, which separate, until the threads enclose an angle of 30^@ , Calculate the charge on each pith-ball.

A stress of 10^7 N m^-2 is required to break a material of density 4 xx 10^4 kg m^-3 . Calculate the length of a wire of this material, which can break under its own weight.

Two identical steel cubes (masses 50 g, side 1 cm) collide head-on face to face with a speed of 10 cm/s each. Find the maximum compression of each. Young's modulus for steel, Y = 2 xx 10^11 N//m^2 .