Answer:
B. The presence of an unbalanced force(e.g friction) causes a moving object to stop.
Explanation:
As the friction is that force that can stop the sled upon reaching the levelled surface so the option b is correct.
Answer: The ratio of atoms of potassium to ratio of atoms of oxygen is 4:2
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed, and remains conserved. The mass of products must be same as that of the reactants.
Thus the number of atoms of each element must be same on both sides of the equation so as to keep the mass same and thus balanced chemical equations are written.
K exists as atoms and oxygen exist as molecule which consists of 2 atoms. The ratio of number of atoms on both sides of the reaction are same and thus the ratio of atoms of potassium to ratio of atoms of oxygen is 4:2.
Answer:
frequency = 5.52 * 10² Hz
Explanation:
the equation that relates velocity, frequency and wavelength is:
velocity = frequency * wavelength
We are given that:
velocity = 331 m/sec
wavelength = 0.6 m
Substitute with the givens in the equation to get the frequency as follows:
velocity = frequency * wavelength
331 = frequency * 0.6
frequency = 331 / 0.6
frequency = 5.52 * 10² Hz
Hope this helps :)
D. Destructive interference. An easy way to think about it is the waves are opposite each other, so they essentially cancel each other out, or make an effort to.
Answer:

Explanation:
Uncertainty principle say that the position and momentum can not be measured simultaneously except one relation which is described below,

Given that the uncertainty in x is 0.1 mm.
Therefore,

Therefore, uncertainty in the transverse momentum of photon is 