a helicopter of mass 800 kg rises to a height of 170 in 20 seconds, before setting off in horizontal flight. calculate the potential energy gain of the helicopter, and hence estimate the mean power of its engine. state a form of kinetic energy that has been ignored in this model.​

Larry bar opened a frame shop and completed these transactions: larry started the shop by investing $41,100 cash and equipment valued at $19,100 in exchange for common stock. purchased $180 of office supplies on credit. paid $2,300 cash for the receptionist's salary. sold a custom frame service and collected $5,600 cash on the sale. completed framing services and billed the client $310. what was the balance of the cash account after these transactions were posted?

Given right triangle a w/a hypotenuse length of x+4 and a leg of x, and right triangle b, w/ a hypotense length of 3y and a leg length of y+4 for what values of x and y are the triangles congruent by hl?

Apasta salad was chilled in the refrigerator at 35° f overnight for 9 hours. the temperature of the pasta dish dropped from 86° f to 38° f. what was the average rate of cooling per hour?