The net force parallel to the plane is
∑ F = m g sin(29°) = m a
where
m = mass of the block
g = magnitude of the acceleration due to gravity, 9.8 m/s²
a = mag. of acceleration of the block
where we take the direction of the block's sliding down the plane to be positive. Then
a = g sin(29°) ≈ 4.8 m/s²
