Answer:
619.8 N
Explanation:
The tension in the string provides the centripetal force that keeps the rock in circular motion, so we can write:

where
T is the tension
m is the mass of the rock
v is the speed
r is the radius of the circular path
At the beginning,
T = 50.4 N
v = 21.1 m/s
r = 2.51 m
So we can use the equation to find the mass of the rock:

Later, the radius of the string is decreased to
r' = 1.22 m
While the speed is increased to
v' = 51.6 m/s
Substituting these new data into the equation, we find the tension at which the string breaks:

Photovoltaic cells are the most efficient means of converting solar energy to electricity. Option b is correct.
<h3>What is a cell?</h3>
A cell is a voltage and current-producing device that consists of a single anode and cathode separated by an electrolyte.
One or more cells can make up a battery. One cell, for example, is one AA battery.
Light intensity on a solar cell is often measured in "suns," with one sun roughly equivalent to 1 kW/m².
Concentrated sunlight improves the ratio of current generated while the device is lighted vs when it is dark, hence enhancing output voltage and efficiency.
Photovoltaic cells are the most efficient means of converting solar energy to electricity.
Hence, option b is correct.
To learn more about the cell refer to:
brainly.com/question/3142913
#SPJ1
This would be typical of an elastic collision.
Answer: One quarter of the force
Explanation:
According to Newton's law of Gravitation, the force
exerted between two bodies of masses
and
and separated by a distance
is equal to the product of their masses and inversely proportional to the square of the distance:
(1)
Where
is the gravitational constant
This means that the gravity force decreases when the distance between these two bodies increases.
In this context, if the distance between the capsule and the Earth increases twice, the new distance will be
.
Substituting this distance in (1):
(2)
<u>Finally:</u>
>>>This means the force toward Earth becomes one quarter "weaker"