Answer:
While the water falls v increases and h decreases, so the kinetic energy increases and the gravitational potential energy decreases, and this happens in a way that the total energy is always the same. (If there is no friction)
Explanation:
<span>d = r*t
t = hours at 20 mi/hr
20t + 12*(4.5 - t) = 70
8t = 16
t = 2 hours
d at 20 mi/hr = 20*2 = 40 miles
40/20 + 30/12 = 4.5 hours
Fiora travels a total distance of 4.5 hours</span>
Answer:
2.43J
Explanation:
Given parameters:
Mass of the arrow = 0.155kg
Velocity = 31.4m /s
Unknown:
Kinetic energy when it leaves the bow = ?
Solution:
The kinetic energy of a body is the energy in motion of the body;
it can be derived using the expression below:
K.E =
m v²
m is the mass
v is the velocity
Solve for K.E;
K.E =
x 0.155 x 31.4 = 2.43J
The answer would be:
B. Chlorine, iodine and Fluorine
Barium has 2 valence electrons. To satisfy the BaX₂ , this would mean that Barium will need to give one of each of its electrons. The elements that need 1 electron would be those that have 7 valence electrons to complete the octet. These elements would fall in group 7 or halogens. Chlorine, iodine and fluorine are all in Group 7, so this would be the best choice.
(a) 0.448
The gravitational potential energy of a satellite in orbit is given by:

where
G is the gravitational constant
M is the Earth's mass
m is the satellite's mass
r is the distance of the satellite from the Earth's centre, which is sum of the Earth's radius (R) and the altitude of the satellite (h):
r = R + h
We can therefore write the ratio between the potentially energy of satellite B to that of satellite A as

and so, substituting:

We find

(b) 0.448
The kinetic energy of a satellite in orbit around the Earth is given by

So, the ratio between the two kinetic energies is

Which is exactly identical to the ratio of the potential energies. Therefore, this ratio is also equal to 0.448.
(c) B
The total energy of a satellite is given by the sum of the potential energy and the kinetic energy:

For satellite A, we have

For satellite B, we have

So, satellite B has the greater total energy (since the energy is negative).
(d) 
The difference between the energy of the two satellites is:
