Answer:
force-strength,power or energy as an attribute of motion, movement or action. Example: Frictional force.
Because other scientists and science in general rely on their collegues' research which in turn allows development of our knowledge on the given subject. The more dont-to-earth reason may be safety. If someone performs an experiment without knowledge of its true results it might result in some danger to the safety of those perforning it without knowledge of all the risks.
Answer:
Speedometer, instrument that indicates the speed of a vehicle, usually combined with a device known as an odometer that records the distance traveled.
Explanation:
Work is performed while initially lifting books off the floor. The work is due to gravity.
