There are lots:
Biology and Medicine - cloning and expression of human insulin in bacteria (stopped having to produce it from pig pancreases); Watson & Crick discovery of the structure of DNA; gene therapy in humans
Chemistry - determination of the exact number of molecules in a mole (Avagadro's number); discovery of radioactivity (Rutherford); the invention of nylon (DuPont); Boyle's law (behavior of gases)
Lead I believe would be the heaviest because gold is relatively light
Answer:
mg of powder 1 and
mg of powder 2
Explanation:
Let "X" denotes weight of powder 1 added to the new mixture and "Y" denotes weight of powder 2 added to the new mixture
Total weight of vitamin B1 in the mixture is equal to
mg
Total weight of vitamin B2 in the mixture is equal to
mg
Equation 1

Equation 2

Let us simplify the above two equations, we will get


Substituting value of X in equation 2 we get

Answer:
If you double the speed of an object, the kinetic energy increases by four times. The word "kinetic" comes from the Greek word "kinesis" which means motion. Kinetic energy can be passed from one object to another in the form of a collision.
Explanation:
The kinetic energy is proportional to the square of the speed, so doubling the speed increases the kinetic energy by a factor of 4.
The energy produced from flow of water or "Hydro-power" is different to energy produced from iron, petroleum and coal as it is a clean and renewable form of energy. Hydro-power is derived from the kinetic energy of the natural flow of water like in the case of a water mill whereas the other forms listed require combustion of the fuel source that produces harmful gases leaving a negative impact on the environment. Also, hydro-power is one of the cheapest forms of energy production.
However, it should be noted that large-scale production of electrical energy from flowing water known as "Hydroelectric Power" uses man-made dams to store water in lakes as a source of potential energy. These dams can also have a negative impact on the environment as the natural flow of water is restricted. Some scientists also suggest that the construction of a dam leads to an increase in the number of earthquakes in and around the area of construction.