Answer:
(a) m1/m2 = 1/3
(b) a = 0.75m/s^2
Step-by-step explanation:
You have the following relations:
For an object of mass m1:
(1)
For an object of mass m2:
(2)
(a) In order to calculate the quotient m1/m2 you use the fact that F1=F2=F.
You divide the equation (1) into the equation (2):

The quotient m1/m2 = 1/3
(b) For the case of a mass of m1+m2, you have:
(3)
To find the values of the acceleration you divide the previous equation into the equation (2):

The new acceleratio for an object of mass m1+m2 is 3/4m/s^2 = 0.75m/s^2