Answer:
Mass of the planet = 1.48 × 10²⁵ Kg
Mass of the star = 5.09 × 10³⁰ kg
Explanation:
Given;
Diameter = 1.8 × 10⁷ m
Therefore,
Radius =
=
or
Radius of the planet = 0.9 × 10⁷ m
Rotation period = 22.3 hours
Radius of star = 2.2 × 10¹¹ m
Orbit period = 407 earth days = 407 × 24 × 60 × 60 seconds = 35164800 s
free-fall acceleration = 12.2 m/s²
Now,
we have the relation
g =
g is the free fall acceleration
G is the gravitational force constant
M is the mass of the planet
on substituting the respective values, we get
12.2 =
or
M = 1.48 × 10²⁵ Kg
From the Kepler's law we have
T² =
on substituting the respective values, we get
35164800² =
or
= 5.09 × 10³⁰ kg
The answer is C. Acceleration is nonzero, but it’s velocity is zero
Answer:
5s
Explanation:
-A period is the time it takes to make one full back-and-forth swing.
-A period is calculated as the time taken for a complete swing divided by one cycle:

Hence, the period of the pendulum is 5s
Answer: mechanical efficieny.
Efficieny is also expressend as percent. The formula for mechanical efficiency as percent is the ratio work output to wor input times 100.
The ideal mechanical efficiency for a machine would be 1 or 100% which means that all the input work is converted into output work. But this is just an idealization as the friction and other losses of energy make it imposible to reach 100% efficiency in reality, so the mechanical efficiency of real machinces is less than 100% or 1.