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.
The momentum law expressed in words is "Impulse = change of momentum."
This law applies when a net force Fnet is applied, for a time interval t, to an object whose mass is M. If the initial velocity is Vo and the final velocity is Vf then the momentum law expressed with symbols is:
Fnet* t = M *Vf - M *Vo
The total time and the average force during the movement of a mass is examined.