Answer:
A. A line can be drawn from the planet to the sun that sweeps out equal areas in equal times
Explanation:
This is exactly what Kepler's second law of planetary motion states:
"the segment joining the sun with the center of each planet sweeps out equal areas in equal time"
This law basically tells how the speed of a planet orbiting the sun changes during its revolution. In fact, we have that:
- when a planet is closer to the Sun, it will orbit faster
- when a planet is farther from the Sun, it will orbit slower
Answer:
The new self inductance is 3 times of the initial self inductance.
Explanation:
The self inductance of a solenoid is given by :

Where
N is number of turns per unit length
A is area of cross section
l is length of solenoid
If length and number of coil turns are both tripled,
l' = 3l and N' = 3N
New self inductance is given by :

So, the new self inductance is 3 times of the initial self inductance.
Answer:
20.62361 rad/s
489.81804 J
Explanation:
= Initial moment of inertia = 9.3 kgm²
= Final moment of inertia = 5.1 kgm²
= Initial angular speed = 1.8 rev/s
= Final angular speed
As the angular momentum of the system is conserved

The resulting angular speed of the platform is 20.62361 rad/s
Change in kinetic energy is given by

The change in kinetic energy of the system is 489.81804 J
As the work was done to move the weight in there was an increase in kinetic energy
Uhh it is used to detirmine heat