Answer:
Explanation:
30 N force is pulling total mass of 15 kg , so acceleration in the system of masses
= 30 / 15
= 2 m / s²
Let us now consider forces acting on 9 kg . 30 N is pulling it in forward direction . Tension T in the string attached to it is pulling it in reverse direction
so net force on it
30 - T
Applying Newton's law of motion on it
30 - T = mass x acceleration
30 - T = 9 x 2
30 - 18 = T
T = 12 N
(a) 
The frequency of an electromagnetic wave is given by:
where
is the speed of the wave in a vacuum (speed of light)
is the wavelength
In this problem, we have laser light with wavelength
. Substituting into the formula, we find its frequency:
(b) 427.6 nm
The wavelength of an electromagnetic wave in a medium is given by:
where
is the original wavelength in a vacuum (approximately equal to that in air)
is the index of refraction of the medium
In this problem, we have
n = 1.48 (index of refraction of glass)
Substituting into the formula,
(c) 
The speed of an electromagnetic wave in a medium is
where c is the speed of light in a vacuum and n is the refractive index of the medium.
Since in this problem n=1.48, we find
12kN is equal to 12000 N
and the perpendicular component will be
[email protected] mg = 12000 N
cos10°= 0.984
thus it will be 12000*0.984 = 11808N
the frictional force will be
[email protected]sin10° = 0.1736
and hence it will be = 2083N
