Two charges q1 and q2 are separated by a distance d and exert a force F on each other. What is the new force F ′ , if charge 1 is increased to q′1 = 5q1, charge 2 is decreased to q′2 = q2/2 , and the distance is decreased to d′ = d 2 ?

According to the tide table below what time of day will the highest tide occur?

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

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.