Answer:
1: toward the normal
2:away from normal
3: red because the index of refraction ( the ratio of the speed of light in a vacuum to the speed of light in a material) is increased for the slower moving waves
Answer:

Explanation:
Given that:

If we let the piece of the close lose contact at ∠θ;
Then ; from force balance;
we have:

where;

Again:

Answer:
Explanation:
Let T be the tension
For linear motion of hoop downwards
mg -T = ma , m is mass of the hoop . a is linear acceleration of CG of hoop .
For rotational motion of hoop
Torque by tension
T x R , R is radius of hoop.
Angular acceleration be α,
Linear acceleration a = α R
So TR = I α
= I a / R
a = TR² / I
Putting this value in earlier relation
mg -T = m TR² / I
mg = T ( 1 + m R² / I )
T = mg / ( 1 + m R² / I )
mg / ( 1 + R² / k² )
Tension is less than mg or weight because denominator of the expression is more than 1.
The formula is CaCl2 as you need two Cl ions in order to combine with one Ca ion in order to form a neutral compound i.e. You need to have the same amount of charges therefore you have two Cl ions which have -1 charges for one +2 Ca ion.
Hope this helps :).