Two tuning forks are played at the same time. one has a frequency of 490 hz and the other is 488 hz. how many beats per second are heard?

Ascientist wants to test ways to reduce pollution in lake . what is the bestway of doing this

Use henry's law and the solubilities given below to calculate the total volume of nitrogen and oxygen gas that should bubble out of 1.7 l of water upon warming from 25 ˚c to 50 ˚c. assume that the water is initially saturated with nitrogen and oxygen gas at 25 ˚c and a total pressure of 1.0 atm. assume that the gas bubbles out at a temperature of 50 ˚c. the solubility of oxygen gas at 50 ˚c is 27.8 mg/l at an oxygen pressure of 1.00 atm. the solubility of nitrogen gas at 50 ˚c is 14.6 mg/l at a nitrogen pressure of 1.00 atm. assume that the air above the water contains an oxygen partial pressure of 0.21 atm and a nitrogen partial pressure of 0.78 atm.

Which statements describe how a machine can make work easier? check all that apply. it can put out more force than the input force by decreasing the distance through which force is applied. it can increase the amount of work performed if the output force is in the same direction as the input force. it can apply a force to an object in a different direction than the force applied to the machine. it can increase the distance through which a force acts by exerting less force than was used on it. it can exert a greater force through a greater distance than the force used on the machine.