Answer:
For a given spring the extension is directly proportional to the force applied For example if the force is doubled, the extension doubles When an elastic object is stretched beyond its limit of proportionality the object does not return to its original length when the force is removed
Explanation:
Answer:
B. twice as much kinetic energy
Explanation:
Lets take the mass of the first marble =2 m
the mass of the second marble = m
We know that velocity of particle does not depends on their mass that is the velocity of both mass will be same after dropping from the roof.
We know that kinetic energy of a mass is given as

Kinetic energy for heavier mass

Kinetic energy for light mass

KE=2 KE '
Form above two equation we can say that ,the kinetic energy for the heavier mass is twice the lighter mass.
Therefore the answer will be B.
So that we do not contaminate it with microorganisms or garbage or other human stuff.