Mechanical waves travel the fastest in
solids and liquids because the
molecules are more closely packed together than gases, so energy is transferred
from one particle to another particle faster<span>.</span>
Distance travelled in south direction= 1.5hr*0.75km/hr= 1.125km
Distance travlled in north direction= 0.90*2.5=2.25
Net displacement = 2.25-1.125= 1.125 to the north
The uncertainty of the heavy object if the scale remains constant is 0.24 lbs.
<h3>What is uncertainty in measurement?</h3>
- This is the error associated in an attempt measure the object accurately.
The percent uncertainty in measuring the light weight object is calculated as follows;

The uncertainty of the heavy object if the scale remains constant is calculated as follows;

Learn more about percent uncertainty here: brainly.com/question/5493941
geyser.........................................