Answer:
The mass of the planet is 
Explanation:
Given that,
Time period = 42 hours = 151200 sec
Orbital radius = 0.002819 AU = 421716397.5 m
Mass of moon 
We need to calculate the mass of the planet
Using Kepler’s third law


Where, a = orbital radius
T = time period
G = gravitational constant
M = mass of moon
m = mass of planet
Put the value into the formula





Hence, The mass of the planet is 
Answer:
Option (B)
Explanation:
In the field of astronomy, the magnitude scale of star is usually defined as a logarithmic scale that measures the brightness of the star, and this directly the relative distance from the earth. This magnitude value is dependent on the two main factors, namely the its brightness and the distance from a fixed point.
The given visual magnitude of a star is 7.3, and is comparatively very less brighter. This shows a relatively very large distance from the earth and due to this large distance and low luminousity, this star is not visible to our naked eye.
Thus, the correct answer is option (B).
Answer:
The maximum kinetic energy of the photoelectrons ejected from the surface is 5.22×10^-20 J.
Explanation:
let h = 6.626×10^-34 J×s be the planck constant.
let f be the frequency of light.
let Ф = 2.20×1.60×10^-19 = 3.52×10^-19 J be the work function.
then, the relationship between the kinetic energy of photoelectrons K, the energy provided by the light E and the work function of the material is given by:
K = h×f - Ф
= (6.626×10^-34)×(6.10×10^14) - 3.52×10^-19
= 5.22×10^-20 J
Therefore, the maximum kinetic energy of the photoelectrons ejected from the surface is 5.22×10^-20 J.
Answer:
270°
Explanation:
A full rotation is 360° so half (2/4) of it is 180° meaning a quarter (1/4) is 90°
So you can do 90+90+90=270
or 180+90=270
Answer:
the answers the correct one is C
Explanation:
In radioactive decay processes, a very important concept is the half-life time, which is the time it takes for the parent nuclei to decompose into child nuclei.
expressed this mathematically is
N = N₀
for the average life time
N₀ / 2 = N₀
T =
Analyzing this expression, the nuclei that decay are the so-called parents and the new nuclei called children appear.
when checking the answers the correct one is C