I believe it’s gas because that’s all that stars are really made of
Answer:
Answer 3: When a balloon goes up higher in the air, its size will increase. Since there's less air in the upper atmosphere, there's less stuff pushing back on the balloon, and hence the pressure is lower, which allows the balloon to expand
Answer: C
Explanation:
As the balloon rises, the gas inside the balloon expands because the atmospheric pressure surrounding the balloon drops. The atmosphere is 100 to 200 times less dense at the float altitudes than on the ground. and as the air is heated inside the balloon it causes it to rise upwards (because it is lighter than the cooler air on the outside). When the pilot needs to bring the balloon down again, he simply reduces the temperature of the air inside the balloon causing it to slowly descend.
<span>We need to start by finding the surface area of the pool.
50 meters multiplied by 25 meters gives us 1250 square meters.
1250 square meters multiplied by .065 (6.5 cm in meters) gives us a volume of 81.25 cubic meters of water that needs to be pumped out of the pool.
There are 1000 liters in a cubic meter so this is 81250 liters. Divide by 4.2 to find the number of seconds required to pump out this much water and we get 19345.2 seconds. This equals approximately 5.37 hours.</span>
First convert the speed of sound from meters/second to miles/second:
Then the time it takes for the sound to travel 20 miles is
Answer:
Explanation:
given,
scattering angle of alpha particle = 25.0° above its initial direction of motion
oxygen nucleus recoils at = 50.0° below this initial direction.
final speed of the oxygen = 2.08×10⁵ m/s
mass of alpha particle = 4.0 u
mass o oxygen nucleus = 16 u
momentum conservation along x- axis
....(1)
Along y-direction
putting value in equation (1)
