Acceleration=force/mass=28/(10+4)=2m/s^2
force10kg=ma=10*2
force4kg=ma=(10*2)=20
the4 kg is pushing against the 10kg block
vf=vi+at
-10=20*28/14 * t
t=30/2=15sec
i hope this can help you.
7.625 Newtons
work = force× distance
Newtons is an accepted value for force
so take the total 224 joules and decide by distance 32 meters to find force in Newtons
Nitrogen isotopes don't have a charge.