For smaller buildings, engineers design elevators to travel slowly because it is more economical. An elevator driven by an electric motor carries a group of people, of total mass 900 kg, to the upper floor of the building. The mass of 900 kg accelerates uniformly from rest to a speed of 4 ms-1, in a time of 3 s, and continues at this speed until it is brought to rest by applying brakes. (i) Calculate the acceleration of the total mass and the force required to produce this acceleration.

Electroplating is a way to coat a complex metal object with a very thin (and hence inexpensive) layer of a precious metal, such as silver or gold. in essence the metal object is made the cathode of an electrolytic cell in which the precious metal cations are dissolved in aqueous solution. suppose a current of 480.ma is passed through an electroplating cell with an aqueous solution of agno3 in the cathode compartment for 46.0 seconds. calculate the mass of pure silver deposited on a metal object made into the cathode of the cell. round your answer to 3 significant digits. also, be sure your answer contains a unit symbol. ×10μ

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.

On average 8 bananas make up one pound. the price is four pounds for 5.00. you must buy 25 bananas.what is your cost?