Answer:
1. The sound waves are longitudinal because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves.
2. A pulse or a wave is introduced into a slinky when a person holds the first coil and gives it a back-and-forth motion. This creates a disturbance within the medium; this disturbance subsequently travels from coil to coil, transporting energy as it moves.
Explanation:
If the distance between two charges is halved, the electrical force between them increases by a factor 4.
In fact, the magnitude of the electric force between two charges is given by:

where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
We see that the magnitude of the force F is inversely proportional to the square of the distance r. Therefore, if the radius is halved:

the magnitude of the force changes as follows:

so, the force increases by a factor 4.
Answer:
80m<em>/</em><em>s</em>
Explanation:
Final velocity is given by
v=u+at
when a motorcyclist starts from rest, initial velocity (u) =0
therefore
v=0+4*20
v=80m/s
that's the answer
Yes the correct answer was
A) The box will not move.