Answer:
The forces of push and pull
Explanation:
In the egg drop experiment, the egg is balanced on top of a toilet paper tube and balanced on a pan. The pan itself is placed on top of a glass of water. When the experimenter uses his hands to push the pan, the force of gravity pulls the egg downwards making it move down, right into the glass of water.
So the two forces which are applied in opposite directions are;
1. The force of push applied horizontally by the hand when it pushes the pan away, and
2. The force of pull caused by gravity which makes the egg move vertically downwards.
Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the friction force on two boxes is given as



Now we know by Newton's II law

so we have




Part b)
For block B we know that net force on it will push it forward with same acceleration so we have




Part c)
If Alex push from other side then also the acceleration will be same
So for box B we can say that Net force is given as




Microwaves are one of the lowest energies on the electromagnetic spectrum. While X-Rays are one of the highest energies on the electromagnetic spectrum. One similarity is that they are both on the electromagnetic spectrum. Also they both travel at the spped of light in a vacuum. One way they are different is They have different frequencies and wavelengths. Also they are used for different studies.
Answer:
The free body diagram of John is shown in the attached figure (in the FBD john's mass is supposed to be concentrated at his center of mass and FBD is made of center of mass)
b) As shown in the FBD the ground reaction forces are:
i) In X direction 
ii) In Y direction 
c) The respective accelerations in x and y direction's is calculated by newton's second law as indicated under

Which elements have similar behavior?
Barium, strontium, beryllium.