Answer: 5.884×10^-19 J
Explanation:
The change in energy will be the product of the planck constant and the frequency of radiation.
ΔE = hf
Where h = planck constant = 6.626×10^-34 m²kg/s
f = 8.88×10^14 Hz
ΔE = 6.626×10^-34 × 8.88×10^14 = 58.84×10^-20 = 5.884×10^-19 J
Answer:
Both forces are the same.
Explanation:
The problem states that:

The force exerted on the moon by earth is given by:
where K is the gravitational constant, and d is the separation distance between the earth and the moon.
The force exerted on the earth by moon is given by:
where K is the gravitational constant, and d is the separation distance between the earth and the moon.
The relation is therefore:

As you can see, they are the same.
Answer:
3. Her angular speed increases because her angular momentum is the same but her moment of inertia decreases
Explanation:
II ωi the intial angular momentum of the skater. Her angular momentum changes to If ωf after pulling her arms in.
It must be noted that If is less than II, then it is because her arms now go round not far from the rotation axis which brings down the mementos of inertia.
Angular momentum does not change since torque is O.
Note: the mathematical representations are better written on the attached diagram.