Search: A block of steel (7900 kg/m3) is suspended from a spring scale. The scale is in newtons.What is the scale reading if the block is in air?What is the scale reading after the block has been lowered into a beaker of oil (900 kg/m3) and is completely submerged?
You have to know how big the block is. Give its mass or its volume.
10cm * 10 cm *10 cm
To find the scale reading in both scenarios, we need to consider the buoyant force acting on the block when it is in air and when it is submerged in oil. The buoyant force is the upward force exerted on an object submerged in a fluid and is equal to the weight of the fluid displaced by the object.
1. Scale reading when the block is in air:
The scale reading when the block is in air is equal to the weight of the block. The weight of an object can be calculated using the formula:
Weight = mass × gravitational acceleration
Given:
Density of steel (ρ_steel) = 7900 kg/m^3
To find the mass of the steel block, we need its volume. Assuming the block has a uniform shape, we can calculate its volume using the formula:
Volume = mass / density
Given that the density of steel is 7900 kg/m^3, we can plug this value into the formula to find the volume of the block.
Once we have the volume, we can calculate the mass using the formula:
Mass = density × volume
Finally, we can calculate the weight of the block using the formula mentioned earlier.
Scale reading = weight of the block
2. Scale reading when the block is submerged in oil:
When the block is submerged in oil, it experiences an upward buoyant force in addition to its weight. This buoyant force depends on the density of the fluid and the volume of the block submerged in the fluid. The buoyant force can be calculated using the formula:
Buoyant force = density of fluid × gravitational acceleration × volume of the block submerged
In this case, the density of the fluid is given as 900 kg/m^3. Similar to the previous calculation, we can find the mass of the block based on its volume and density. Then, we can use the buoyant force formula to determine the scale reading.
Scale reading = weight of the block - buoyant force
By following these steps and performing the calculations, we can find the scale reading in both scenarios.