Aconstruction worker drops a hammer from a height of 50 feet. after how many seconds does the hammer land on the ground? round your answer to the nearest hundredth.

7l07 sec

Step-by-step explanation:

The pertinent equation is s(t) = -16t^2.  We set this equal to zero to denote hammer hitting ground:  -16t^2 = -50 ft.  Solve for t^2 by dividing both sides by -16, obtaining

t^2 = 50 ft^2

The time required for the hammer to reach the ground is Sqrt(50 ft^2),

or 7.07 sec

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

step-by-step explanation: