A 40 kg machine pushes with  a 200N force, a 60 kg box on a horizontal floor, without friction. What will be the acceleration of the box and machine?

QUESTION 4
As the angle θ between two force vectors decreases continuously from +90° to -90°, the resultant R of the two vectors:
a. increases  
b. decreases  
c. increases at first, then decreases  
d. decreases at first, then increases
e. none of the above