Question

Железное ведро массой 1,08 кг и объёмом 13 л опустили в колодец. Определи, какую силу надо приложить, чтобы поднять полное ведро в воде и над водой. Принять g = 9,8Н/кг. Трение не учитывай. Ответ (округли до десятых): чтобы поднять полное ведро в воде, необходимо приложить силу Н, а над водой - силу H.

Answer 1

Ответ:

ρж=7800 кг/м3  

Vo=13*10^-3 м3    

ρв=1000 кг/м3

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F1=m*g-ρв*g*V

V=m/ρж

F1=m*g*(1-ρв/ρж)=1,08*9,8*(1-1000/7800)≈9,2 Н

F2=m*g+ρв*g*Vo=1.08*9.8+1000*9.8*13*10^-3≈137,9 H

Answer 2

Calculation of the Force Required to Lift the Bucket

To determine the force required to lift the full bucket of water, we can use the equation:

Force = Mass x Acceleration due to gravity

Given that the mass of the bucket is 1.08 kg and the acceleration due to gravity is 9.8 N/kg, we can calculate the force as follows:

Force = 1.08 kg x 9.8 N/kg

Calculating this, we find that the force required to lift the full bucket of water is approximately 10.6 N.

Calculation of the Force Required to Lift the Empty Bucket

To determine the force required to lift the empty bucket, we need to consider the buoyant force acting on the bucket when it is submerged in water. The buoyant force is equal to the weight of the water displaced by the bucket.

Since the bucket is completely submerged in water, the volume of water displaced is equal to the volume of the bucket, which is given as 13 liters.

To calculate the force required to lift the empty bucket, we can use the equation:

Force = Mass of water displaced x Acceleration due to gravity

The mass of water displaced can be calculated using the density of water, which is approximately 1000 kg/m³.

Mass of water displaced = Density of water x Volume of water displaced

Converting the volume of water displaced from liters to cubic meters:

Volume of water displaced = 13 liters x (1/1000) m³/liter

Calculating this, we find that the volume of water displaced is approximately 0.013 cubic meters.

Now, we can calculate the mass of water displaced:

Mass of water displaced = 1000 kg/m³ x 0.013 m³

Calculating this, we find that the mass of water displaced is approximately 13 kg.

Finally, we can calculate the force required to lift the empty bucket:

Force = 13 kg x 9.8 N/kg

Calculating this, we find that the force required to lift the empty bucket is approximately 127.4 N.

Therefore, to summarize: - The force required to lift the full bucket of water is approximately 10.6 N. - The force required to lift the empty bucket is approximately 127.4 N.