When lisa placed a balloon to her ear, she was able to hear what her sister was whispering from the other side of the room. when she removed the balloon, she was no longer able to hear what her sister was saying. what is the best explanation for what lisa discovered?

Explanation :

Helium gas is present inside air balloon. Its density is less than air i.e. it is lighter than air.

The speed of sound in air is 343 m/s and around 972 m/s in He.

So, when Lisa placed a balloon to her ear, she was able to hear what her sister was whispering from the other side of the room because the sound waves are travelling with faster speed to Lisa.

When she removed the balloon, she was no longer able to hear what her sister was saying. It is because speed of sound in air is 343 m/s.

The answer is D

Explanation:

Sound does not travel around the air outside of the balloon as well as it does through the denser air pressure inside the balloon

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.