it is estimated thet 7×10⁶ kg of wazer pours over the niagera falls every second. if the falls are 50 meter high, and if all the energy of falling water could be harnessed, what power would be available?(g=10 N/kg)

An object weighs 40n in air, weighs 20n when submerged in water and 30n when submerged in a liquid of unknown density. what is the density of the liquid?

Road users moving into your lane, brake lights, and abrupt changes in road surface are a. rare at night b. indicators of potential hazards c. not worth worrying about before you reach them d. no problem for experienced drivers

How many times did thomas edison mess up the light bulb