AboutJames J. Kovalcin Expertise I am teaching or have taught AP physics B and C [calculus based mechanics & electricity and magnetism] as well as Lab Physics for college bound students. I have a BS in Physics from the University of Pittsburgh and a Master of Arts in Teaching from same. I have been teaching physics for 34 years. I am constantly updating my skills and have a particular interest in modern physics topics.
We want to constuct and float a barge on a 10m deep water. The carrying capacity of the raft should be at least 15 tones (15,000kg).
I wanted to know:
1)Size of the barge (area and height)including its submerged height.
2) What method we should use to get buoyancy
3) If we can construct the raft from locally available materials (steel, timber, oil drum, iron sheet)
4) How we can stablize it so that the barge should stay at its position?
Thank you
Yohanes
Answer The buoyancy force on he barge will be equal to the weight of the water displaced by the barge. In order to support a load of 15,000 kg the boar will have to displace at least 15,000 kg of water. Since the mass of water is 1000 kg per cubic meter this barge will have to displace at least 15 cubic meters of water. Any combination of length x width x depth [V=L*w*d] that is at least 15 cubic meters will be able to support the barge. Being realistic, however, you should make the barge a bit more, perhaps 20 cubic meters, so that the side of the barge is above the water line. [I have seen river barges where the deck is only a few centimeters above the water line. Another factor is to consider the material from which the barge is to be made because the weight of the construction material must also be included. Every 1000 kg of construction material will increase the required displacement of the barge by another cubic meter.
Staying in position? That would seem to require a motor.
