Question

need answer with solution​

Answer 1

$\huge{\bold{\underline{\underline{....Answer....}}}}$

$\huge{\bold{\underline{Given:-}}}$

• Edge of the box = l
• Angle of inclination = ${ \alpha}$
• Initial velocity = 0 m/s.

$\huge{\bold{\underline{Explanation:-}}}$

For F.B.D

#refer the attachment for figure.

As the bolt will be falling down the acceleration due to gravity should be taken as :-

a = g cosα.

(As it is acting downwards w.r.t block)

Now, Applying second kinematic equation,

$\large{\bold{S = ut + \dfrac{1}{2} at^2}}$

Substituting the values,

$\large{S = 0 + \dfrac{1}{2} \times g \cos \alpha \times t^2}$

Now,

$\large{l = \dfrac{1}{2} \times g \cos \alpha \times t^2}$

$\large{g \cos \alpha \times t^2 = 2l}$

$\large{t^2 = \dfrac{2l}{g \cos \alpha}}$

$\large{t = \sqrt{ \dfrac{2l}{g \cos \alpha}}}$

$\huge{\boxed{\boxed{t = \sqrt{ \dfrac{2l}{g \cos \alpha}}}}}$

So, the correct option is (A).