Power=Work/Time
The work done is the energy required to lift the box, fighting the force of gravity. So, Work=Potential energy of the box at 10 meters.
W=PE=mgh=(60)(9.8)(10)=5880J
Finally,
P=W/T=(5880)/(5)=1176Watt
So the answer is 1176 Watts
Answer:
The pressure after passing the valve is 23,8 [Kpa] ( 0,234 atm) and the pressure drop is about 1,53 [Kpa]
Explanation:
We need to use the formula of bernoulli, in the attached image we can see the fluid throw the pipe, we also can calculate the velocity inside the pipe using the flow rate and the cross sectional area.
For this case, we don't use the elevation difference and therefore those terms can be cancelled.
When the area has reduced the velocity of the fluid is increased but there is a drop pressure through the valve.
Given
initial position = Xi= 19.9m
Final position Xf = 5.4m
Average velocity= Va = -0.418m/s
it shows displacement is reverse.
To find t=?
As Va = (Xf- Xi) / t
t = (Xf-Xi) / ( Va)
t = ( 5.4-19.9) / (-0.418)
t = (-14.5 ) / (-0.418) (-ve sign cancel out at numerator and denominator)
t =34.69 s
Answer:
Correct answer: P₂ = 25 W
Explanation:
Given: voltage V₁ = 220 V, power P₁ = 100 W, V₂ = 110 V, P₂ = ?
The formula for calculating power is:
P = V · I
We will include in the story and ohm's law:
I = V/R
We will replace the current in the expression for power
P = V · V/R = V²/R ⇒ R = V²/P
We will first calculate the electrical resistance of the bulb which is a constant in the electrical circuit
R = V₁²/P₁ = 220²/ 100 = 48,400 / 100 = 484 Ω
Power consumption of bulb connected to 110 V is:
P₂ = V₂²/R = 110²/484 = 12,100/484 = 25 W
P₂ = 25 W
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