Answer:

Explanation:
The magnitude of the gravitational force between two objects is given by the equation:

where
G is the gravitational constant
m1, m2 are the masses of the two objects
r is the separation between the objects
The gravitational force is always attractive.
In this problem, we have:
is the mass of the Earth
is the mass of the Moon
is the separation between the Earth and the Moon
Therefore, the gravitational force between them is

Electromagnetic waves do not require a medium to travel through. They can travel through empty space or matter.
Answer:
31
Explanation:
Given:
U=3
X=4
Y=7
u + xy
Substitute the given values to the equation:
3 + (4)(7)
3 + 28
31
To solve this problem, we will get f and then we will use it to calculate the power.
So, for this farsighted person,
do = 25 cm and di = -80
Therefore:
1/f = (1/25) + (1/-80) = 0.00275 = 0.275 m
Power = 1/f = 1/0.275 = +3.6363 Diopeters.
This means that the lens is converging.