Answer:
The acceleration expressed in the new units is 
Explanation:
To convert from
to
it is necessary to remember that there are 1000 meters in 1 kilometer and 3600 seconds in 1 hour:
Then by means of a rule of three it is get:


Hence, the units of meters and seconds will cancel. Notice the importance of square the ratio 3600s/1h, so that way they can match with the other units:

So the acceleration expressed in the new units is
.
Elastic Potential Energy because the elasticity in the string stores up the energy.
Answer:
Sink
Explanation:
The normal density of water is 1 g/cm3. Since the rock has a higher density of 1.72g/cm3, it will sink in water.
A lot of it is all experimental as long as you are taking caution of safety while doing it. I personally would use copper wiring mainly for the fact that it is a nice conductor. For the wrap around the wiring i usually would use black or red electrical tape just because it has very nice insulator properties and is safe to use.