Two movers use a rope system to lift a box to a third-story apartment. they do 1,200 j of work on the rope system, and the rope system does 1,020 j of work on the box. what is the efficiency of the rope system?

Sara is creating an experiment. her hypothesis states the following. if i increase the air in my tires, then i will get better gas mileage. if this is her hypothesis what column titles do we need in our date table? a. air pressure in tire (psi) and gas mileage (mph) b. air pressure in the atmosphere (psi) and gas mileage (mph) c. miles (m) and gallons per mile (g) d. old battery and new battery

The temperature at a point (x, y) is t(x, y), measured in degrees celsius. a bug crawls so that its position after t seconds is given by x = 6 + t , y = 8 + 1 3 t, where x and y are measured in centimeters. the temperature function satisfies tx(3, 9) = 5 and ty(3, 9) = 4. how fast is the temperature rising on the bug's path after 3 seconds? (round your answer to two decimal places.)

Apositive charge moves in the direction of an electric field. which of the following statements are true? check all that apply. check all that apply. 1.the potential energy associated with the charge decreases. 2. the electric field does positive work on the charge. 3. the electric field does negative work on the charge. 4. the potential energy associated with the charge increases. 5. the electric field does not do any work on the charge. 6. the amount of work done on the charge cannot be determined without additional information.