Solution:

Just release the ball at the top of an incline and the one that reaches bottom will be the solid ball.

Explanation:
The solid ball has a smaller moment of inertia and hence less mechanical energy is spent on rotating the ball and therefore it will reach earlier.

Solution:

It's marked as shown below.

Solution:

Future.

Solution:

TH

Explanation:
1st 2nd 3rd 4th 5th

Solution:

TIF56

Explanation:
The password is formed as:
T (5th letter of Shruti)
I (5th letter of Arshika)
F(1st letter of Friday)
5(5th day of week)
6(Length of Friday)

Similarly, we will pick the 1st letter for Monday and 3rd letter for Wednesday.

Solution:

LION.

Explanation:
It can be done as shown in the picture below

Solution:

12 Angry Men

Explanation:
12 (dozen = 12)
Angry (Angry Bed)
Men

Solution:

Treasure Map Is Hidden Inside The Hanging Room Floor.

Explanation.
Just reverse the text "roolF mooR gnignaH ehT edisnI neddiH sI paM erusaerT".

Solution:

On Your lap.

Solution:

(C)