Answer:
b. The normal force between the molecules of the paper is overcome by the contact force of the hands.
Explanation:
The paper molecules are held together by a weak bond. When the student holds the paper on both sides with the center of the paper in between, the student applies two equal forces in the opposite direction of the paper making the paper molecules weaken and separate.
Answer:
c. 2 m/s
Explanation:
The relationship between speed, frequency and wavelength of a wave is given by:

where
v is the speed of the wave
f is its frequency
is the wavelength
For the transverse wave in this problem, we have:
is the frequency
is the wavelength
Substituting these numbers into the equation, we find the speed of the wave:

Answer:
The object is also positively charged because same or alike charges repel
Explanation:
Answer:
2625 m deep
Explanation:
Let the sound speed in sea water be 1500 m/s. If he hears the echo 3.5s after the strike, then the sound would have traveled a distance of 1500 * 3.5 = 5250 m to the bottom and back. This would mean the ocean is 5250 / 2 = 2625 m deep.
The answer is d my friend :)