<p>These are two physics problems that we had on a test today, and I just can't figure out how to approach them.</p>

<p>A weightlifter who has a mass of 56 kg lifts a barbell that has a mass of 175 kg (I think those were the numbers...and yes, his mass was something small). Find the force exerted on each of his feet at the point where he is lifting the barbell at an acceleration of 1.0 m/s^2.</p>

<p>(No clue how to approach this problem. I said that the force exerted on his two feet combined was equal to: (175 kg)(9.8 m/s^2) + (175 kg)(1.0 m/s^2), because that's how much was necessary to overcome the gravity of the dumbbell.)</p>

<p>A wooden box of mass 10 kg is on an incline of 25 degrees. It is connected to a rope which is strung over a pulley at the top of the incline. On the other end is a hanging bucket of mass 2 kg. The coefficient of static friction is 0.50, and the coefficient of kinetic friction is 0.36. Find the acceleration of the block. </p>

<p>(In order to solve the problem, you need to find the friction...don't you first need to know whether it's moving or not, in order to know which coefficient to use?)</p>

<p>Thanks...</p>