Describe the construction and working of nicol prism

The velocity of a Falling Hammer During the construction of a high-rise apartment building, a construction worker accidentally drops a hammer that falls vertically a distance of h feet. The velocity of the hammer after falling a distance of x feet is:

Find the average velocity of the hammer.

Two identical springs are composed in a parallel construction.They are stretched 3cm by a mass of 3kg. The springs are then setup in a serie construction. How much will they stretch now?

Construction A construction worker pulls a five-meter plank up the side of a building under construction by means of a rope tied to one end of the plank (see figure). Assume the opposite end of the plank follows a path perpendicular to the wall of the building and the worker pulls the rope at a rate of 0.15 meter per second. How fast is the end of the plank sliding along the ground when it is 2.5 meters from the wall of the building?