Answer:
A flame always point upwards because the flame's gas is hotter than the surrounding air and, like you said, a hot gas is always lighter or less dense than a cold gas.
Explanation:
This problems a perfect application for this acceleration formula:
Distance = (1/2) (acceleration) (time)² .
During the speeding-up half: 1,600 meters = (1/2) (1.3 m/s²) T²
During the slowing-down half: 1,600 meters = (1/2) (1.3 m/s²) T²
Pick either half, and divide each side by 0.65 m/s²:
T² = (1600 m) / (0.65 m/s²)
T = square root of (1600 / 0.65) seconds
Time for the total trip between the stations is double that time.
T = 2 √(1600/0.65) = <em>99.2 seconds</em> (rounded)
Answer:
(a) 89 m/s
(b) 11000 N
Explanation:
Note that answers are given to 2 significant figures which is what we have in the values in the question.
(a) Speed is given by the ratio of distance to time. In the question, the time given was the time it took the pulse to travel the length of the cable twice. Thus, the distance travelled is twice the length of the cable.

(b) The tension,
, is given by

where
is the speed,
is the tension and
is the mass per unit length.
Hence,

To determine
, we need to know the mass of the cable. We use the density formula:

where
is the mass and
is the volume.

If the length is denoted by
, then


The density of steel = 8050 kg/m3
The cable is approximately a cylinder with diameter 1.5 cm and length or height of 620 m. Its volume is




<span>The question says: complete the sentence: The distance between stars is typically measured in.... The answer is 'light years" - the distance that light travels in a year. That's because it's a very big unit and if we were using smaller units, we would be using huge numbers that would be hard to read and would take up a lot of space.</span>
Answer:
1.89mol
Explanation:
The entropy change during free expansion is express as

Where S is the entropy of the system,
n is the amount of mole
R is the gas constant = 8.314 and
V is the volume occupied at the initial and final stage
since the process is n adiabatic free expansion, the entropy of the system is constant. Hence we can re-write the equation as

where the
and 
and
Now if we substitute in values we arrive at
