Question

A cube of mass 10 kg and side 5 cm is placed on a horizontal surface A force F is applied along face CD as shown Choose the correct statement(s)

• A. If 50 < F < 100 then acceleration of centre of mass is zero
• B. The normal on cube due to the surface must be 100 N
• C. Cube will begin to move when applied force is just greater than 50 N
• D. The normal on cube due to surface may be 60 N

Answer 1

Answer: (C), (D)

The correct options are
C Cube will begin to move when applied force is just greater than 50 N
D The normal on cube due to surface may be 60 N

$Force=mg=10\times 10$

$=100N$

At $E$ point, Force=$F$

to move,$F\times \frac{5}{2}>(100-F)\times \frac{5}{2}$

$=2F>100$

$=F>50$

So, is applied force is just greater than $50N$, then the cube will move.

Similarly if the normal force is greater than $50N$, then it would be possible.