What kind of scientific investigations do not involve experiments?

in a thermal power plant, heat from the flue gases is recovered in (A) chimney (B) de-super heater (C) economizer (D) condenser

How much work will it take to lift a 2-kg pair of hiking boots 2 meters off the ground and onto a shelf in your closet? O A. 2.45 J B. 4J C. 39.2 J D. 20 J

You are located in New York, NY, United States. Your friend is located in Panama City, Panama. You see a waning gibbous in your clear night sky. What phase, if any, will your friend see if the night sky in Panama City is also clear?

What is the speed of a bobsled whose whose distance time graph indicates that it traveled 113 m in 30 s

In hydroelectric dams, gravitational potential energy is used to produce electrical energy. What is the mass of water that must fall over a dam that is 12 m high in order to produce the same amount of energy in an AA battery (10,800 J) ?

How do air quality scientists ensure the air is cleaned? What steps do they take?

Is a mirrors surface opaque or transparent or translucent?

Sound waves can combine to become bigger or smaller true or false

Archimedes supposedly was asked to determine whether a crown made for the king consisted of pure gold (density of gold is 19.3 * 103 kg/m3). According to legend, he solved this problem by weighing the crown first in air and then in water.

What are at least three types of energy involving a microwave