A string going over a massless frictionless pul- ley connects two blocks of masses 4.2 kg and
3.8 kg. As shown on the picture below, the
4.2 kg block lies on a 23° incline; the coefli-
cient of kinetic friction between the block and
the incline is u= 0.23. The 3.8 kg block is
hanging in the air.
The 3.8 kg block accelerates downward
while the 4.2 kg block goes up the incline
with the same acceleration.
If gravity is constant (g=9.8), what is the acceleration of the system?