a scale ranking ten minerals from softest to hardest; used in testing the hardness of minerals. Define DENSITY: A measure of how much matter there is in a given amount of space.
Jerusalem is a hilly city so the altitude varies but it is approximately 750 Meters (2,500 feet) above sea level.
Angle of elevation is the angle formed by the line of sight of an observer with the horizontal while he is viewing an object upward. The angle of elevation is a degree measure indicating the gradient of the line of sight. As this angle can be measured using devices, this measure can be used to determine large heights and long distances, which are impractical to physically measure.