Home
Class 9
PHYSICS
A mass of M kg is suspended by a weightl...

A mass of M kg is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of `45^@` with the initial vertical direction is

A

`Mg (sqrt(2)-1)`

B

`Mg (sqrt(2)+1)`

C

`Mg sqrt(2)`

D

`(Mg)/(sqrt(2))`

Text Solution

Verified by Experts

The correct Answer is:
A
Work done in displacement is equal to gain in potential energy.
Work done `=F xx l sin45^(@)=(Fl)/(sqrt(2))`
Gain in potential energy
`=Mg (l-l cos 45^(@))`
`=Mgl (1-(1)/(sqrt(2))) :. (Fl)/(sqrt(2)) =(Mgl (sqrt(2)-1))/(sqrt(2))`
or `F=Mg (sqrt(2)-1)`
Promotional Banner

Topper's Solved these Questions

  • WORK AND ENERGY

    SCIENCE OLYMPIAD FOUNDATION |Exercise ACHIEVERS SECTION (HOTS) |5 Videos

  • SOUND

    SCIENCE OLYMPIAD FOUNDATION |Exercise ACHIEVERS SECTION (HOTS) |5 Videos

Similar Questions

Explore conceptually related problems

A mass M is suspended by a weightless string The horizontal force required to hold the mass 60^(@) with the vertical is .

Derermine the horizontal force required to displace a mass of 0.03 kg suspended by a string until the string makes an angle 30^(0) with the vertical.

A body of mass sqrt3 kg is suspended by a string to rigid support.The body is pulled horizontally by a force F until the string makes an angle of 30^(@) with the vertical.The value of F and tension in the string are

A mass of 10 kg is suspended from a spring balance. It is pulled aside by a horizontal string so that it makes an angle of 60^(@) with the vertical. The new rading of the balance is

A stone of mass 1 kg is whirled in horizontal circle attached at the end of a 1 m long string. If the string makes an angle of 30^(@) with vertical, calculate the centripetal force acting on the stone. (g=9.8" m"//"s"^(2)) .

A bob of mass m attached to an inextensible string of length l, is suspended from a vertical support. Bob rotates in a horizontal circle with angular speed omega and string makes an angle of theta with the vertical. Find the angular momentum of bob about axis of rotation

A heavy particle of mass 1kg suspended from a massless string attached to a roof. A horizontal force F is applied to the particle such that in the equilibrium position the string makes and angle 30^(@) with the vertical. The magnitude of the force F equals .

A mass of 10 kg is suspended from a spring balance, it is pulled aside by a horizontal string so that it makes an angle 60^(@) with the vertical. The new reading of the balance is: