Air is made of 80% nitrogen and 20% oxygen by volume. the densities of air and oxygen is 1.29kgm^-3 and 1.43kgm^-3 respectively. what is the density of nitrogen? specify your soultion, you!

If forces acting on an object are unbalanced. true or false

Adolphin emits ultrasound at 100khz and uses the timing of reflections to determine the position of objects in the water. part a what is the wavelength of this ultrasound? assume that temperature of water is 20 degrees c. answer in cm

Which of these statements best explains how the hydrosphere interacts with the atmosphere to affect global climate? mountains block rain clouds and cause changes in global rainfall and evaporation. humans burn fossil fuels to produce greenhouse gases which cause global warming. humans cut down trees which affects the amount of oxygen in different parts of the globe. greenhouse gases, like carbon dioxide, dissolve in oceans and prevent global warming.