The torque of a force vecF=-3hati+hatj+5...

The torque of a force `vecF=-3hati+hatj+5hatk` acting at a point is `vectau`. If the position vector of the point vector of the point is `7hati+3hatj+hatk`, then `vectau` is :

A

`14hati - 38hatj + 16hatk`

B

`4 hati - hatj + 6hatk`

C

`-14hati+ 38hatj - 16hatk`

D

`-21hati + 3hatj + 5hatk`

Text Solution

Verified by Experts

The correct Answer is:

A

Heree `tau=vec(r )xxvec(F)`
`tau=(7hati+3hatj+hatk)xx(-3hati+hatj+5hatk)`
`=-14hati-38hatj+16hatk`

Promotional Banner

Promotional Banner

Topper's Solved these Questions

DESCRIPTION OF MOTION IN TWO AND THREE DIMENSION
MODERN PUBLICATION|Exercise MCQ(LEVEL-III)(Questions from AIEEE/ JEE Examinations)|6 Videos
DESCRIPTION OF MOTION IN TWO AND THREE DIMENSION
MODERN PUBLICATION|Exercise RECENT COMPETITIVE QUESTIONS|7 Videos
DESCRIPTION OF MOTION IN TWO AND THREE DIMENSION
MODERN PUBLICATION|Exercise Revision TEST|36 Videos
DESCRIPTION OF MOTION IN ONE DIMENSION
MODERN PUBLICATION|Exercise Revision Test|45 Videos
E.M. INDUCTION AND A.C. CURRENTS
MODERN PUBLICATION|Exercise RECENT COMPETITIVE QUESTIONS|31 Videos

Similar Questions

Explore conceptually related problems

The position vectors of A and B are hati-hatj+2hatk and 3hati-hatj+3hatk . The position vector of the middle points of the line AB is

If the position vectors of P and Q are (hati+3hatj-7hatk) and (5hati-2hatj+4hatk) , then |PQ| is

Find the torque of a force 7hati + 3hatj – 5hatk about the origin. The force acts on a particle whose position vector is hati – hatj + hatk .

Find the projection of the vector hati+3hatj+hatk on the vector 7hati-hatj+8hatk

Find the projection of the vector hati+3hatj-7hatk on the vector 7hati+hatj+8hatk

If the position vectors of A and B respectively hati+3hatj-7hatk and 5 hati-2hatj+4hatk , then find vec(AB)

Find the projection of the vector veca = 2 hati + 3hatj + 2hatk on the vector vecb = hati +2hatj +hatk

MODERN PUBLICATION-DESCRIPTION OF MOTION IN TWO AND THREE DIMENSION-MCQ(LEVEL-II)

If |vec(a) + vec(b)| = |vec(a) - vec(b)| then
Text Solution
|
An aeroplane is flying at a height of 2000 m above the ground horizont...
Text Solution
|
The torque of a force vecF=-3hati+hatj+5hatk acting at a point is vect...
Text Solution
|
The position vectors of radius are vec(r(1))=2hati+hatj + hatk , vec(r...
Text Solution
|
A force vector applied on a mass is represented by vec(F)=6hati + 8hat...
Text Solution
|
Which vector should be added to 2hati + 4hatj -3hatk and 3hati-5hatj+7...
Text Solution
|
The sum of the magnitude of two vectors is 18. The magnitude of their ...
Text Solution
|
If unit vectors vec(A) and vec(B) are inclined at an angle theta then ...
Text Solution
|
Angle which the vector vec(A)=2hati + 3hatj makes with the y-axis is g...
Text Solution
|
If the magnitude of the vector product is sqrt(3) times the magnitude ...
Text Solution
|
A particle of mass m = 5 is moving with uniform speed v = 3sqrt(2) in ...
Text Solution
|
The velocity of projection of an oblique projectile is (6hati + 8hatj)...
Text Solution
|
A projectile is thrown at angel with vertical. It reaches a maximum he...
Text Solution
|
A ball is projected from a certain point on the surface of a planet at...
Text Solution
|
If the air resistance causes a vertical retardation of 10% of value of...
Text Solution
|
A body is thrown horizontally with a velocity sqrt(2gh) from the top o...
Text Solution
|
The range of the projectile for a given initial velocity of projection...
Text Solution
|
A ball is projected at an angle 30° with the horizontal. What is the c...
Text Solution
|
A particle is projected at an angle of 45° from the foot of a wall, ju...
Text Solution
|
The equation of projectile is y=sqrt(3)-g/2x^(2) , the angle of its pr...
Text Solution
|