Answer: 134 neutrons are there in the nucleus of Radon-220
Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
Thus, number of protons = atomic number = 86
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Mass number = Number of protons + Number of neutrons
220 = 86 + Number of neutrons
Number of neutrons = 134
Seven days after a waxing gibbous moon, the moon will be waning gibbous, and at some point during that seven days, it will have been Full.
Answer:
Resultant force, R = 10 N
Explanation:
It is given that,
Force acting along +x direction, 
Force acting along +y direction, 
Both the forces are acting on a point object located at the origin. Let the resultant force of the object is given by R. So,

Here 


R = 10 N
So, the resultant force on the object is 10 N. Hence, this is the required solution.
Answer:
68.8 N
Explanation:
From the question given above, the following data were obtained:
Mass (m) of box = 18 Kg
Coefficient of friction (μ) = 0.39
Force of friction (F) =?
Next, we shall determine the normal force of the box. This is illustrated below:
Mass (m) of object = 18 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Normal force (N) =?
N = mg
N = 18 × 9.8
N = 176.4 N
Finally, we shall determine the force of friction experienced by the object. This is illustrated below:
Coefficient of friction (μ) = 0.39
Normal force (N) = 176.4 N
Force of friction (F) =?
F = μN
F = 0.39 × 176.4
F = 68.796 ≈ 68.8 N
Thus, the box experience a frictional force of 68.8 N.
Answer:
a. 0.18Hz
b. 0.56m/s
Explanation:
From the question we can deduct the following parameters
The wavelength, λ is define as the distance between two successful crest or trough and from the question we conclude that wavelength is 3.17m.
Also the period of the wave T can be computed as
T=22.6/4
T=5.65secs.
a. To compute the frequency, recall that frequency, F=1/period.
Hence,
F=1/5.65
F=0.18Hz
b. Next we compute the wave speed.
Wave speed=frequency *wavelength
Wave speed =0.18*3.17
Wave speed =0.56m/s