Arubber ball weighs 49 n.. a) what is the mass of the ball? ( 5.0 kg). b) what is the acceleration of the ball if an upward force of 69 n is applied? ( 4.0 m/s/s). for a) i used the equation w = fg = mg, which becomes 49 = m(9.8). this approximates m to 5.0 kg.

for b) i used the equation
σfy=fa−w=ma
which becomes 69-49 = 20 n.
i then use equation f = ma which becomes 20 = 5.0a, which makes a
4.0m/s2