On a frictionless ice a variable force P in Newtons, expressed by P= 5 + 6 t, is applied to an initially stationary block of wood to move it across the ice until its final speed is V= 25 m/sec. The mass of the wood is M= 3 kg. Vectors P and V are in the same direction.
a. Find the time, in seconds, that the force is applied.
b. Find the average force during the force application.