Answer
Given,
Sirius A surface temperature,T = 9400 K
Sirius A luminosity,L = 26 L₀
L₀ is the luminosity of sun.
Radius of sun = 695700000 m
Temperature on sun surface = 5780 K
Luminous intensity is given by:-
Now

Answer:
The correct option is that (She decreases her moment of inertia, thereby increasing her angular speed.)
Explanation:
When an object is in circular motion, the vector that describes it is known as angular momentum. Angular momentum is conserved or constant when an object is spinning in a closed system and no external torques are applied to it. An example of conservation of angular momentum is seen when a woman is sitting on a spinning piano stool with her arms extended. Her angular momentum is conserved because the net torque on her is negligibly small as the friction is exerted very close to the pivot point.
When she folds her arms,her rate of spin increases greatly decreasing her moment of inertia. The work she does to pull in her arms results in an increase in rotational kinetic energy( that is, increase in her angular speed). I hope this helps, thanks!
Answer:5.60 m/s
Explanation:
Given
Coefficient of static friction 
Coefficient of kinetic friction 
mass of crate 
Force applied 
maximum static Friction 



thus applied force is greater than Static friction therefore kinetic friction will come into play


net Force on crate 

Magnitude of velocity can be obtained by using

where v=final velocity
u=initial velocity
a=acceleration
s=displacement
here initial velocity is zero as crate start from rest


Answer:
The area is 15.502 km².
The fraction is 
Explanation:
Given that,
Daily average insolation = 6 kWh/m²
Efficiency = 20%
Population = 324 million
Per capita power = 1378 watts
Area of tennessee = 109250 km²
We need to calculate the daily power required
Using given data

Put the value into the formula



We need to calculate the total energy per day
Using given data


We need to calculate the out of total energy
Using energy and efficiency



We need to calculate the area
Using formula of area

Put the value into the formula


We need to calculate the fraction of Tennessee that is required to power
Using given data

Put the value into the formula


Hence, The area is 15.502 km².
The fraction is 
If a problem says the acceleration is some positive value than solve using that value, a negative acceleration is said to be deceleration. E.g. a car decelerating at 10 m/sec can be said to be accelerating at -10 m/sec.
If a problem states decelerates at A, then use -A for acceleration in the classic equations which are for acceleration. If a problem says accelerates at a negative value like -A the use -A as the value for acceleration, it can also be said to be decelerating at A.