1. What is the mass of a bird that is moving at 20 m/s if the bird has momentum of 40 kgm/s? *

m = 2 kg

Explanation: Momentum is expressed as the product of mass and velocity. So to find the mass, we will derive the formula for momentum. p = mv, mass is

m = p/v

= 40 kg. m/s / 20 m/s

= 2 kg

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.