Answer:
Explained
Explanation:
The cheater pipe extends the wrench in radial direction, providing a larger momentum for the force you exert.
For a given force the torque exerted with the cheater pipe is larger.
Mathematically we can write that
τ = r×F and τ'= r'×F
now since r'> r
⇒ F'>F
calculate the power per hour of a radiator, knowing that it is connected to a common 110 v contact. and requires 20 Amp.
Answer:
2.2kWh
Explanation:
Given parameters:
Potential difference = 110v
Current = 20A
Unknown:
Power = ?
Solution:
To solve this problem, we use the expression below:
Power = IV
Power = 110 x 20 = 2200W
This is therefore 2.2kW
Power per hour = 2.2kWh
Answer:
A. Conduction
Explanation:
Conduction is the transfer of heat within the material itself, and he's holding the metal bar over the fire.
Answer:
96%
Explanation:
To find the values of the motor efficiency you use the following formula:

P_o: output power = 864J/0.5min=864J/30s=28.8W
P_i: input power = I*V = (3A)(12V) = 36W
By replacing this values you obtain:

hence, the motor efficiency is about 96%
traslation:
Pentru a găsi valorile eficienței motorului, utilizați următoarea formulă:
P_o: putere de ieșire = 864J / 0.5min = 864J / 30s = 28.8W
P_i: putere de intrare = I * V = (3A) (12V) = 36W
Înlocuind aceste valori obțineți:
prin urmare, eficiența motorului este de aproximativ 96%