can someone check this?

[badboyben03]

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?

[jamesrc]

The horizontal component of the tension should be 400*cos(30)~346 N

The sum of forces in the x direction is then 346 - 75 = ma

solve for a ~ 3.9 m/s/s.