Give the oppositesof :
Height above sea level.

Give the oppositesof : -8

Give the oppositesof : 20 .

Give the oppositesof : Going North

Give the oppositesof : Rise in water level.

Give the oppositesof : Temperature below zero.

Write opposites of the following, 100 m above sea level.

As observed from the top of a light house, 100 m high above sea level, the angle of depression of a ship, sailing directly towards it, changes from 30^@ to 45^@ . Determine the distance travelled by the ship during the period of observation.

A hemi-spherical tank of radius 2 m is initially full of water and has an outlet of 12c m^2 cross-sectional area at the bottom. The outlet is opened at some instant. The flow through the outlet is according to the law v(t)=0.6sqrt(2gh(t)), where v(t) and h(t) are, respectively, the velocity of the flow through the outlet and the height of water level above the outlet and the height of water level above the outlet at time t , and g is the acceleration due to gravity. Find the time it takes to empty the tank.