In the overhead view of Fig. 5-4a, a 2.0 kg cookie tin is accelerated at 3.0 m/s2 in the direction shown by d, over a frictionless horizontal surface. The acceleration is caused by three horizontal forces, only two of which are shown: F_1 of magnitude 10 N and F_2 of. magnitude 20 N. What is the third force F_3 when the direction of the F_1 is 126-degrees.
