)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?
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.
physics repost - Damon, Wednesday, April 16, 2008 at 6:01am
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