I am needing help on a few problems that I have to do for class. If anyone could help on any of them that would be great. 1)Bob, who has a mass of 75 kg, can throw a 500 g rock with a speed of 30 m/s. The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 m. a. What constant force must Bob exert on the rock to throw it with this speed? b. If Bob is standing on frictionless ice, what is his recoil speed after releasing the rock? 2) a block of mass rests on a 20 deg slope. The block has coefficients of friction 0.8 (static) and 0.5 (kinetic) with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg. a. What is the minimum mass that will stick and not slip? b. If this minimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will it have? 3) The coefficient of static friction is 0.60 between the two blocks in figure. The coefficient of kinetic friction between the lower block and the floor is 0.20. Force causes both blocks to cross a distance of 5.0 m, starting from rest. a. What is the least amount of time in which this motion can be completed without the top block sliding on the lower block? I have already tried doing these problems many times each and am running out of chences to be wrong so I am just hoping someone out there who is better in physics can come up with the right way to do it! Thanks!