HELP PLZ AND THANK U A system with one fixed and one movable pulley operates with 90% efficiency. The movable pulley has a weight of 5 N. Using this pulley system, what is the minimum input force needed to lift a piano weighing 1,595 N?

What makes thermal imaging cameras useful? they can detect differences in color. they can detect differences in wave speeds. they can detect differences in temperature. they can detect mechanical waves.

Acompound machine is also called a machine. a. force b. simple c. complex d. directional

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely