Answer:
0.8%
Explanation:
We are given;
Number of oscillations; n = 20
Time taken; t = 25 s
Formula for period of oscillation;
T = t/n = 25/20 = 1.25 s
We are told that the least count is 0.2 s. Thus, error is; ΔT = 0.2 s
percentage error in the measurement of time is given by;
(0.2/(20 × 1.25)) × 100% = 0.8%
the Doppler effect. (I don't know how to explain it lol)
To solve this problem we will use the concepts related to gravitational acceleration and centripetal acceleration. The equality between these two forces that maintains the balance will allow to determine how the rigid body is consistent with a spherically symmetric mass distribution of constant density. Let's start with the gravitational acceleration of the Star, which is

Here



Mass inside the orbit in terms of Volume and Density is

Where,
V = Volume
Density
Now considering the volume of the star as a Sphere we have

Replacing at the previous equation we have,

Now replacing the mass at the gravitational acceleration formula we have that


For a rotating star, the centripetal acceleration is caused by this gravitational acceleration. So centripetal acceleration of the star is

At the same time the general expression for the centripetal acceleration is

Where
is the orbital velocity
Using this expression in the left hand side of the equation we have that



Considering the constant values we have that


As the orbital velocity is proportional to the orbital radius, it shows the rigid body rotation of stars near the galactic center.
So the rigid-body rotation near the galactic center is consistent with a spherically symmetric mass distribution of constant density
Given parameters:
Mass on earth = 50kg
Unknown:
Mass on planet Xenon = ?
Weight on planet Xenon = ?
Mass is the amount of matter contained in a particular substance.
Weight is the force on a body and it is derived from the product of mass and acceleration due to gravity.
Weight = mass x acceleration due to gravity
Planet Xenon has half the gravitational force of Earth.
This translated gives
= 4.9m/s²
Now, mass is always the same every where if the amount of matter in a substance does not change.
In this problem, mass = 50kg on planet xenon.
Weight = mass x acceleration due to gravity = 50 x 4.9 = 245N
The weight on Xenon is 245N and the mass is 50kg