Which is not a medium through which a mechanical wave could travel? liquid water jump rope oxygen gas empty space

An airplane flies eastward and always accelerates at a constant rate. at one position along its path it has a velocity of 34.3 m/s, it then flies a further distance of 40100 m and afterwards its velocity is 47.5 m/s. find the airplane\'s acceleration and calculate how much time elapses while the airplane covers those 40100 m.

A2.00-m long piano wire with a mass per unit length of 12.0 g/m is under a tension of 8.00 kn. what is the frequency of the fundamental mode of vibration of this wire?

Aflask with vinegar in it has a mass of 160 grams. a balloon with baking soda in it has a mass of 40 grams. the balloon is attached to the flask to seal the opening and the vinegar and baking soda mixes. the balloon inflates to a large volume. what will the total mass of the balloon and flask be after the balloon inflates? explain. a) less than 200 grams because the solid baking soda disappears. b) 200 grams, because all the atoms remain in the balloon or flask. c) more than 200 grams because the size of the balloon is so much larger. d) less than 200 grams because gases such as the one in the balloon are lighter than solids and liquids.