Answer:
8.00 kJ
Explanation:
The first thing is to determine what quantities are there.
the mass of water = 1 000 kg
initial velocity, u = 6 m/s
final velocity, v = 4 m/s
the generator is operating at 100 % efficiency, so there is no energy loss.
The kinetic energy, Ek is converted to electrical energy, therefore Ek = electrical energy.
The kinetic energy is calculated as follows:
Ek = 1/2 mv²
= 1/2×(1 000)× (4)²
= 8 000 J/s
= 8.00 kJ Ans
Answer:
Explanation:
Given the parallex of the star is 0.1 sec.
The distance is inversely related with the parallex of the star. Mathematically,
Here, d is the distance to a star which is measured in parsecs, and P is the parallex which is measured in arc seconds.
Now,
And also know that,
Therefore the distance of the star is away.
Any one trial might have been done incorrectly.
Answer:
It is possible because, the TV broadcast audio and video signals in radio frequency which travels at the speed of light while the audio signals travel to those present in the stadium at the speed of sound which is over eight hundred thousand times slower than the speed of light
Explanation:
It is possible because of the following;
1. TV signals from the camera (including the captured sound) very close to the field of play are transmitted through the radio frequency bands and as such are a form of electromagnetic radiation that travels at the speed of light which is about 300,000 km/second
It will therefore, take 1 second for a sound of the game to reach someone located at 300,000,000 meters watching a live televised game
2. The speed of sound is about 343 m/second and it therefore takes up to 2 seconds for a sound to reach someone 686 meters away from the ball in the stadium.
Answer:V=Aq=KQr
Explanation:
Không biết V bạn kí hiệu ở đây là gì nhỉ? Có phải là điện thế?
Điện thế tại 1 điểm trong điện trường được định nghĩa là công làm vật dịch chuyển từ vị trí đó đến vô cùng. V = A/q
Chứng minh thì được, nhưng chỉ e bạn không có hiểu biết về nguyên hàm, tích phân nên không hiểu.
- Xét tại vị trí cách điện tích Q một đoạn x, khi đó điện tích q sẽ chịu 1 lực: dF=KQ.qx2
Điện tích q dịch chuyển 1 khoảng dx rất nhỏ. Khi đó công do lực điện trường gây ra là:
dA=dF.dx=KQ.qx2dx
Công để dịch chuyển điện tích q từ vị trí r đến vô cùng là:
A=∫∞rdA=∫∞rKQ.qx2dx=KQ.qr−KQ.q∞=KQ.qr
Theo đúng định nghĩa: V=Aq=KQr
