a 70 kg box s pulled by a 400 N force at an angle of 30 degrees to the horizontal. The force of kinetic friction is 75 N. determine the acceleration. heres what i did first i found the x-component using (686)sin30 and it comes out to be 343. Then i use the formula where the sum of forces = m*a and i plug in the numbers. 343=70a. divide by a and accelertaion is 4.9 m/s/s. is that right?