)An elevator is moving down with an acceleration of 1.40 m/s^2. A 14.5 kg block hangs from a spring balance fixed to the roof of the elevator. What is the apparent weight of the block?

m*g+m*a
14.5*9.80+14.5*1.40
142.1+20.3
162.4 N

2)A 2.7 kg box is released on a horizontal surface with an initial speed of 2.9 m/s. It moves on the surface with a deceleration of 0.27 m/s^2. Calculate the kinetic friction force on the box.

F=m*a
2.7*0.27
0.729 N

It is accelerating down, not up.

9.8-1.4 = 8.4
8.4 * 14.5 = 121.8 N

F= m g mu = m a
yes