1/f= 1/di+1/do
1/f=1/90m+1/40m
1/f ≈27.7m
<span>The three main types of stress in a rock are shearing, tension, and compression. hope. that helped</span>
Energy is the ability to do work or cause change. There are basically
two main types of energy, kinetic and potential. Potential energy is
energy that is stored. There are various types of stored, or potential
energy. Chemical energy from a battery is a potential form of energy,
elastic energy in a stretched rubber band is a form of potential energy,
but the most commonly referred to form of potential energy in physics
is that of gravitational potential energy. This is energy that is
stored due to an object's position. It is dependent on the mass of the
object, the height of the object above the ground or Earth, and the acceleration due to gravity.
The gravity is pushing rhe boat down
A laser is worked by electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation".