You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard VIII

Physics

Force

A disc is rot...

Question

A disc is rotating with angular velocity w, a force f acts at a point whose position vector with respect to the axis of rotation is vector r. The power associated with torque due to the force is given by (1) (r X f).w (2) (r X f)Xw (3) rX( f.w) (4) r. (f X w)

Open in App

Solution

Suggest Corrections

Similar questions

Q. Suppose that a rigid body is free to rotate about a fixed point

O

. If a force

F

acts on the body at a point

P

, then the body will tend to rotate about an axis through

O

. This effect is measured by the torque vector

t

which is given by

t = r \times F

where

r

is the position vector

O P

. The straight line through

O

determined by

t

is the axis of rotation. The vector

r, F

and

T

form a right handed system.

The magnitude of the torque exerted at origin by the force

F = i + 2 j + k

at the point

(1, 1, 1)

Q. A force

\to F = 4^i - 10^j

acts on a body at a points having position vector

- 5^i

- 3^j

relatives to origin of co-ordinates on the axis of rotation . The torque acting on body is

Q. Suppose that a rigid body is free to rotate about a fixed point

O

. If a force

\to F

acts on the body at a point

P

, then the body will tend to rotate about an axis through

O

. This effect is measured by the torque vector

t

which is given by

\to t = \to r \times \to F

. Where

\to r

is the position vector

- - \to O P

. The straight line through

O

determined by

\to t

is the axis of rotation. The vector

\to r, \to F

and

\to T

form a right handed system.
A bolt is being tightened by a

20 N

force is applied to a

25 c m

long wrench at an angle of

60^{0}

with the wrench. The magnitude of torque is

Q. A force

\to F = 4^i - 10^j

acts on a body , at a point having position vector

- 5^i - 3^j

relative to origin of co-ordinate on the axis of rotation. The torque acting on the body about the origin is :

Q. Suppose that a rigid body is free to rotate about a fixed point

O

. If a force

\to F

acts on the body at a point

P

, then the body will tend to rotate about an axis through

O

. This effect is measured by the torque vector

t

which is given by

\to t = \to r \times \to F

. Where

\to r

is the position vector

- - \to O P

. The straight line through

O

determined by

\to t

is the axis of rotation. The vector

\to r, \to F

and

\to T

form a right handed system.
The magnitude of the torque

(in units)

exerted at origin by the force

\to F =^i + 2^j +^k

at the point

(1, 1, 1)

Join BYJU'S Learning Program