Answer:
13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.
Explanation:
Length of the base = l
Width of the base = w
Height of the pyramid = h
Volume of the pyramid = 
We have:
Rate at which water is filled in cube = 
Square based pyramid:
l = 6 cm, w = 6 cm, h = 13 cm
Volume of the square based pyramid = V





Differentiating V with respect to dt:




Putting, h = 4 cm


13.20 cm/s is the rate at which the water level is rising when the water level is 4 cm.
Answer :
(A) Br₂ (s) : molecular solids
(B) AgCl (s) : ionic solids
(C) S (s) : atomic solids
(D) CH₄ (s) : molecular solids
Explanation :
Molecular solids : It is defined as the solids in which they are held together by covalent forces, dipole interactions as attractive forces etc.
Ionic solids : It is defined as the solids in which the atoms composed with oppositely charged ions.
Atomic solids : It is defined as the solids in which the molecules are held together by covalent forces and also includes pure substance.
(A) Br₂ (s)
It is molecular solids because they are held together by covalent forces.
(B) AgCl (s)
It is ionic solids because in this atoms composed with oppositely charged ions.
(C) S (s)
It is atomic solids because it is a pure substance.
(D) CH₄ (s)
It is molecular solids because they are held together by covalent forces.