The amount of energy required to raise the temperature of one gram of water by one Celsius degree is called a

Where do magnetic lines of force enter earth?

If frequency goes up, what happens to wavelength? does it get shorter or longer?

50 points to who answers this question in a clear and simple explanation : to what hight will a mass of weight of 500 n be raised in 20 seconds by a motor using 4kw of power?