a. 7.0 m/s
First of all, we need to convert the angular speed (1200 rpm) from rpm to rad/s:

Now we know that the row is located 5.6 cm from the centre of the disc:
r = 5.6 cm = 0.056 m
So we can find the tangential speed of the row as the product between the angular speed and the distance of the row from the centre of the circle:

b. 
The acceleration of the row of data (centripetal acceleration) is given by

where we have
v = 7.0 m/s is the tangential speed
r = 0.056 m is the distance of the row from the centre of the trajectory
Substituting numbers into the formula, we find

Answer Choices:
a. Technician A only
b. Technician B only
c. Both technicians A and B
d. Neither technician A nor B
Explanation:
a. Technician A only
Answer:
- 0.6
Explanation:
Given that angle between normal y axis is 62° so angle between normal
and x axis will be 90- 62 = 28 °. Since incident ray is along x axis , 28 ° will be the angle between incident ray and normal ie it will be angle of incidence
Angle of incidence = 28 °
angle of reflection = 28°
Angle between incident ray and reflected ray = 28 + 28 = 56 °
Angle between x axis and reflected ray = 56 °
x component of reflected ray
= - cos 56 ( it will be towards - ve x axis. )
- 0.6
Check the attached file for the answer.