Two objects (45.0 and 21.0 kg) are connected by a massless string that passes over a massless, frictionless pulley. the pulley hangs from the ceiling. find (a) the acceleration of the objects and (b) the tension in the string.

In a system, when potential energy decreases, then entropy also decreases. true false

An alien spaceship is 500 m above the ground and moving at a constant velocity of 150 m/s upwards. how high above the ground is the ship after 5 seconds?

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3