NEETPhysicsRotational Motion
A uniform cube of mass (m ) and side (a ) is placed on a frictionless horizontal surface. A vertical force (F ) is applied to the edge as shown in figure. Match the following (most appropriate choice) ( array |c|l|c|l| & Column I & & Column II (a) & m g/4 m g/2 & (q) & Cube will not exhibit motion (c) & F > m g & (r) & Cube will begin to rotate & & & and slip at A (d) & F = m g/4 & (s) & Normal reaction effectively a
Options
- Aa-p b-r c-s d-q
- Ba-p b-s c-r d-q
- Ca-q b-r c-p d-s
- Da-q b-p c-s d-r
Correct answer
C. a-q b-r c-p d-s
Step-by-step solution
Consider the below diagram Moment of the force (F ) about point (A, ₁=F a ) (anti-clockwise) Moment of weight (m g ) of the cube about point (A ), ( ₂=m g a 2 (clockwise) ) Cube will not exhibit motion, if ( ₁= ₂ ) ( ( ) In this case, both the torque will cancel the effect of each other] ( array ll & F a=m g a 2 & F= m g 2 array ) Cube will rotate only when, ( ₁> ₂ ) ( F a>m g a 2 F> m g 2 )