Keeping in mind that the conversion between calories and Joules is

we can write the conversion factor using the kilocalories:

The energy released in our problem is
so we can set a simple proportion to find its equivalent in kcal:

from which we find:
Answer:
(a) Angle of incidence for violet is more than the angle of incidence for red
(b) 2.4°
Explanation:
refractive index for violet , v = 1.66
refractive index for red, nR = 1.61
wavelength for violet, λv = 400 nm
wavelength for red, λR = 700 nm
Angle of refraction, r = 30°
(a) Let iv be the angle of incidence for violet.
Use Snell,s law
nv = Sin iv / Sin r
1.66 = Sin iv / Sin 30
Sin iv = 0.83
iv = 56°
Use Snell's law for red
nR = Sin iR / Sin r
where, iR be the angle of incidence for red
1.61 = Sin iR / Sin 30
Sin iR = 0.805
iR = 53.6°
So, the angle of incidence for violet is more than red.
(b) iv - iR = 56° - 53.6° = 2.4°
Answer:
The force is unbalanced
Explanation:
After an arrow is shot, the force acting on the arrow is unbalanced. The resulting net force gives the arrow an initial acceleration which wanes with time and the body is brought to rest.
The net force acting on an arrow is not zero and this indicates that the forces acting on the arrow is unbalanced.
If the force is balanced, the arrow is expect to continue in uniform motion but that is not the case as air resistance has massive impact on this body.
Explanation:
Below is an attachment containing the solution
Two significant figures, the 6 and the 9