A plane is traveling eastward at an airspeed of 500 km/h. But a 90 km/h wind is blowing south- ward. What are the direction and speed of the plane relative to the ground?
VO

Answerstatic electricity shock;

Perpendicular to the wave motion 

If element x has 21 protons, element x has 21 electrons

In the conservation of mass, mass (which is the same as energy) can never be created or destroyed in the same way oil is formed from the remains of small animals and plants that died and fell to the bottom of the sea and their mass (energy) is conserved as oil.