Acertain radar installation tracks airplanes by transmitting electromagnetic radiation of wavelength 4.0 cm.
a)find the frequency of this radiation. b)find the time required for a pulse of radar waves to reach an airplane 4.8 km away and return.

A500g object falls off a cliff and losers 100 j from its gravitational potential energy store. if the gravitational field strength g=9.8n/kg, how high is the cliff?

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

What is the rate of 12 liters of water moving through a water hose in 4.0 minutes?