Answer:
A. Atoms randomly crashing into each other
E. The force of one object pushing against the force of another object.
Explanation:
Forces can be classified into two categories based upon the the mode of transfer or application:
1. Contact forces
2. Non-contact forces
Contact forces are the ones which require the physical contact of the matter to get transferred and tend to create the affect. Whereas non-contact forces have the field property which transfers the affect of force from one point to another without any physical contact of the matter or the medium.
- Atoms crashing onto each other have some mass and velocity which upon collision impacts the other atoms exerts a contact force.
- The interaction between the charged particles due to their charges is always due to the electric field be it electron or proton, be it within an atom or out of an atom.
- The force between any two objects pushing or pulling each other is also possible only due to contact.
Ga, 31 electrons/ protons, 39 neutrons
Answer:
definite volume. indefinite shape
<h3>Question :</h3>
Which of the following sources could not be used to obtain the DNA of a person lost in a mass disaster?
- used and unwashed clothing or bed sheets
- food found in the victim's refrigerator
- sunglasses regularly used by the person
- a toothbrush used by the person
<h3>Answer :</h3>
food found in the victim's refrigerator could not be used to obtain the DNA of a person lost in a mass disaster.
So, correct answer is 2nd one.
