I think i used calulater and it gives me 47.5
In order to tell a river lock attendant that you wish to go through the lock, you should <span>sound one prolonged blast followed by one short blast.
You should wait about 400 feet away from the lock and wait for the flashing light signal that allows you to enter.
Also note that </span><span>commercial traffic always have the first priority in entering the locks.</span>
Answer:
The center of mass for the object is
from the origin
Explanation:
From the question we are told that
The mass of the first object is 
The position of first object with respect to origin 
The mass of the second object is 
The position of second object with respect to origin 
The mass of the third object is 
The position of third object with respect to origin 
The mass of the fourth object is 
The position of fourth object with respect to origin 
Generally the center of mass of the object along the x-axis is zero because all the mass lie on the y axis
Generally the location of the center mass of the object is mathematically represented as

=>
=>
The Factors are Temperature and kinetic energy, the temperature is because the particles are going to move fast which means the particles in a solid container or in solid pattern they will actually vibrate and they will expand , when temperature increase, more kinetic energy between the particles .
examples is that in the steel when you heat a steel the particles inside it will vibrate then the particles speed up because the vibration increases, therefore the temperature increases so a a thermal expansion occurs that the vibration of the particles will take up more space so the steel bar expands slightly in all Direction if the temperature Falls the reverse happens and the material or steel contracts which means get smaller .
another example is the thermometer, the thermometer has a liquid inside it which is Mercury or alcohol this liquid expands when the temperature rises, the tube is made narrow so that a small increase in volume of the liquid produces a large movement along the tube.