When the boat submerges completely in the pond, the water level of the pond rises.
Factors influencing friction
The magnitude of friction is contingent on the following elements: i) The surface area in contact. ii) The applied pressure on the surfaces. Force is determined by Pressure multiplied by Area; thus, if the contact area increases or if the pressure applied rises, the frictional force will also escalate.
Methods for reducing friction
i) Smooth the contact surface. ii) Apply oil or grease to fill small gaps in flat surfaces. iii) Use ball bearings to minimize contact area among rotating components.
Lubrication
To minimize friction, various methods may be employed: Oil can be either thin or viscous, which depends on its SAE number (SAE indicating Society of Automotive Engineers). Highly viscous oils may not reach all components effectively. In contrast, very thin oils may drain away quickly, resulting in wastage. Grease is preferable in such situations, particularly around ball-bearings. Regular grease or oil should not be utilized under high speed, high pressure, and high temperature conditions—specialized lubricants are required then. The consistency of oil varies with temperature; it thickens in the cold and thins in the heat. Therefore, the choice of lubricant should be seasonally appropriate, and it's always wise to consult the equipment's operating manual prior to making a selection.[[TAG_11]]
Incomplete query. The complete inquiry is as follows
Calculate the torque exerted on the shaft of a vehicle transmitting 225 hp at a rotation speed of 3000 rpm.
Response:
Torque=0.51 Btu
Analysis:
Given Information
Power=225 hp
Revolutions =3000 rpm
To determine
T( torque )=?
Process
As an object is moved by force over a distance, work is performed on that object. Similarly, when torque rotates an object through an angle, work is also accomplished.

Answer:
The total energy saving achieved will be 0.8 KWH
Explanation:
It is provided that there are 50 long light bulbs rated at 100 W, thus the total power consumed by 50 bulbs equals 100×50 = 5000 W = 5 KW
Additionally, 30 bulbs are rated at 60 W
Consequently, the total power consumption of 30 bulbs is 30×60 = 1800 W = 1.8 KW
The cumulative power of all 80 bulbs is 1.8 + 5 = 6.8 KW
Considering the operation time of 3 hours
We know that energy 
Now, the power consumption per CFL bulb equals 25 W
Thus for 80 bulbs, power equals 80×25 = 2000 W = 2 KW
So the energy for 80 bulbs amounts to 2×3 = 6 KWH
Hence, the overall energy saving is 6.8 - 6 = 0.8 KWH
The formula to apply is expressed as:
ρ = nA/VcNₐ
where
ρ signifies density
n represents the number of atoms within a unit cell (for FCC, n=4)
A indicates the atomic weight
Vc stands for the cubic cell volume equal to a³, with a being the side length (for FCC, a = 4r/√2, where r is the radius)\
Nₐ denotes Avogadro's number, which is 6.022×10²³ atoms/mol
Calculating the radius: r = 0.1387 nm*(10⁻⁹ m/nm)*(100 cm/1m) = 1.387×10⁻⁸ cm
Then find a: a = 4(1.387×10⁻⁸ cm)/√2 = 3.923×10⁻⁸ cm
Then calculate V: V = a³ = (3.923×10⁻⁸ cm)³ = 6.0376×10⁻²³ cm³
Now compute density:
ρ = [(4 atoms)(195.08 g/mol)]/[(6.0376×10⁻²³ cm³)(6.022×10²³ atoms/mol)]Finally, we get ρ = 21.46 g/cm³