Define universal gravitational constant. Why is Newton's law of gravitation called universal law?​

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

Suppose you have a box. which of these is not necessarily a true statement regarding the relationship between the force applied to the box, the work done on the box, and the distance the box is moved? a. if the box is not moved, no force is being applied to the box. b. if no force is applied to the box, no work is done on the box. c. if work is done on the box, then a force is applied to the box. d. if work is done on the box, then the box is moved a distance.

Which one of the following research methods can show cause and effect