1. The problem statement, all variables and given/known data 1. A 2kg block sits on a 4kg block that is on a frictionless table. The coefficients of friction between the blocks are 0.3 (the static) and 0.2 (the kinetic). a. what is the max F that can be applied to the 4kg block if the 2kg block is not to slide. b. If F is half this value, find the acceleration of each block and the force of friction acting on each block. 2. m1 =250g is at rest on a plane that makes an angle of 30 degree above the horizontal. The coefficient of kinetic friction between the block and the plane is 0.100. The block is attached to a second block of m2= 200g that hangs freely by a string that passes over a frictionless and massless pulley. When the 2nd block has fallen 30cm, its speed is ??? (a) 83 cm/s (b)48 cm/s (c)160 cm/s (d) 59 cm/s (e) 72cm/s 2. Relevant equations F=ma, Fx= coeff * Fn 3. The attempt at a solution So I got part a right which is 17.7N. However, I got part b wrong. 1/2 of F= 8.85N. Fs,2 = coeff * Fn = 0.3.2.9.81= 5.9 N Is this right ?? I got marked wrong on this one but cannot figure out why. 2. So I draw FBD and wrote Newton's 2nd law for each block and get m2 - Fn*coeff of friction -m1g*sin[tex]\theta[/tex] =(m1 +m2)*a. So I got a and use Vf2 = 2a[tex]\Delta[/tex]x I got around 14...cm/s so I chose c but it's wrong. Can you guys help me ??