Question 1 : A petrol engine has a work output of 96kJ per minute. What is the power I put if the engine efficiency is 20%? Question 2 : A crane lifts a load of 500kg to a height of 120m in 16s. If the power input is 45 000W, what is the efficiency of the motor used in the crane?

Sound is a disturbance that travels through a medium as a

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?

In a series circuit the __ is the same at every point