A large passenger ship weighs 75,000 tonnes and has a cruising speed of 45 km/h. The engines burn diesel fuel (approximately the same energy content as crude oil) with an efficiency of 20%. The drive system has an average efficiency of 55% for converting mechanical energy into propulsion for the ship. Calculate the volume of fuel, in litres, needed to accelerate the ship from rest to cruising speed.

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 10.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.90 m/s; (b) he is then lifted at the constant speed of 4.90 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 68.0 kg rescue by the force lifting him during each stage?

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?

What component of earth’s atmosphere exists entirely as a result of photosynthesis?