Physics electricity in grade two -- electric power (very simple) A "3000r / kW · H" watt hour meter is used by a student to measure the total power of his home circuit when it works normally. If the turntable turns 30 turns in one minute, what is the total power of his home circuit at this time?

Physics electricity in grade two -- electric power (very simple) A "3000r / kW · H" watt hour meter is used by a student to measure the total power of his home circuit when it works normally. If the turntable turns 30 turns in one minute, what is the total power of his home circuit at this time?

30*60/3000=0.6KW
In the triangle area formula s = 2 / 1Ah (a is one side of the triangle, h is the height on this side), if a is fixed, h is an independent variable,
If h is fixed and a is an independent variable, then the constant is (), () is the function of (),
Then 2 / 1a is a function of (constant) area s and (high H),
The formula is s = (1 / 2) ah;
If h is fixed and a is an independent variable, then the constant is (high H) and (area s) is a function of (edge a)
The formula is s = (1 / 2) ah;
I'm a sophomore, too
Then 2 / 1a is a function of (constant) area s and (high H),
The formula is s = (1 / 2) ah;
If h is fixed and a is an independent variable, then the constant is (high H) and (area s) is a function of (edge a)
The formula is s = (1 / 2) ah;
If h is fixed and a is an independent variable, then the constant is (H) and (s) is a function of (a)
adopt!!! One
It is known that the sum of the first n terms of the sequence {an} is Sn, A2 = 4, and satisfies 2Sn = n (an + 1) (n ∈ n *) (1) find A1, A3, A4
It is known that the sum of the first n terms of the sequence {an} is Sn, A2 = 4, and satisfies 2Sn = n (an + 1) (n ∈ n *)
(1) Find the values of A1, A3 and A4, and guess the general term formula of the sequence {an}
(2) Let BN = (- 1) ^ n × an, use the conclusion of (1) to find the first 15 ideas and TN of the sequence {BN}
It should be 2Sn = n & nbsp; a (n & nbsp; + 1)
a1：2S1=1*a2,a1=S1=2
a3：2S2=2*a3,a3=S2=a1+a2=6
a4：2S3=3*a4,a4=2/3S3=2/3(a1+a2+a3)=8
We can guess: an & nbsp; = & nbsp; 2n
bn = (-1)^n * 2n
Tn = b1+b2+b3+b4+...+b15
=-2+4 -6+8 ...-30
=(-2+4)+( -6+8) ...-30
=2+2+2+2+2+2+2 -30
= -16
（1）an=3n-2
(2) BN - (- 1) BN
Second year physics (electric work and electric power)
1. Two electric lamps of 6v3w and 6v6w are connected in series to the 6V power supply. What is their actual power? Which lamp is on? What is their electric power? What is the ratio of power?
2. Lamp L1 is marked with 6v3w and lamp L2 is marked with 9v3w. Connect them to the battery pack. It is found that only one lamp lights normally and the other lamp is very dark. What is the current of the main road at this time? What is the actual power of each lamp?
In a word, how to calculate the actual power? Is not the actual voltage multiplied by the actual current? But only the rated voltage and rated power?
I don't quite understand the second question. What's the difference between parallel connection and series connection? What's dark is another light. Please add,
The actual power of 3W is 1.33w, and the actual power of the other is 0.67w. The higher the actual power is, the brighter the lamp is. So the 3W lamp is on, and the power ratio is OK
2. The normal lighting is either 6V or 9V, but the title says that the lamp is very dark, so it can only be 6V normal lighting, and according to the safe use of electricity, it can also be judged that it is 6V. Since L1 is normal lighting, its power is 3W, L2's power is 1.33w, and the total power of the parallel circuit is the sum of the power of each branch. Add up the two powers, and then I = P / u can calculate the current of the main circuit
Conclusion:
1. If you know the specification of the light bulb in series, you can calculate the resistance and then the voltage at both ends of the light bulb through series positive voltage
2. A good formula: P real / P amount = (U real) ^ 2 / (U amount) ^ 2
Universal can also replace u with I
Supplement: in the case of parallel connection of two lamps in question 2, the voltage at both ends of each branch is equal, that is, the power supply voltage is 6V
Because of the difference of resistance, the voltage at both ends of each consumer in series is different, and the voltage ratio of two consumers is equal to the resistance ratio
According to the title, it is known that the normal lighting voltage of L1 should be 6V, and that of L2 is 9V (remember: for electrical appliances, there will only be one corresponding power under their rated voltage, i.e. the top power). However, according to P = u ^ 2 / R, the smaller u, the same R, the smaller P. therefore, the actual voltage of the dark electrical appliance should be less than the rated voltage, which can only be 9V (and, If it is 9V, the power supply voltage will be 9V and L1 will burn off.)
Do you understand? I started to learn electricity is also very dizzy
VB: calculate triangle area by programming
Program to calculate the triangle area. Input the three side lengths a, B and C of the triangle through the input box. When you click the command button "calculate", calculate and display the triangle area in the text box
It is suggested that the formula of triangle area is area = SQR (s * (s - a) * (s - b) * (s - C))
Where s = (a + B + C) / 2
Note: the three sides of the triangle are to judge whether they conform to form a triangle!
Private Sub Form_ Load()
Do
Dim a As Single,b As Single,c As Single,p As Single,s As Single
A = Val (InputBox ("please input the first side length of triangle"))
B = Val (InputBox ("please input the second side length of triangle"))
C = Val (InputBox ("please input the third side length of triangle"))
s = (a + b + c) / 2
If a >= s Or b >= s Or c >= s Then
Msgbox "cannot form triangle"
Else
area = Sqr(s * (s - a) * (s - b) * (s - c))
Msgbox "area is" & Area
End If
Loop
End
End Sub
If M > 1, am-1 + am + 1-am & # 178; = 0, s2m-1 = 38, then what is m equal to?
Why am can't be equal to 0?
Because it is an arithmetic sequence, for any continuous three terms a (m-1), a (m), a (M + 1), there are:
a(m-1)+a(m+1)=2a(m)
In the title:
a(m-1)+a(m+1)-a(m)²=0
So a (m) ² = 2A (m)
The results are as follows
Or m (a) = 0
We know that for the arithmetic sequence:
S(2m-1)=(2m-1)*a(m)
that is
(2m-1) * 2 = 38 or (2m-1) * 0 = 38
Therefore, it is concluded that:
m=10
In a series circuit, a 300 ohm resistor and a 1000 ohm resistor are connected in series. Do they pass the same current?
In other words, in series, the current is equal and the voltage is added to get the total voltage; in parallel, the voltage at both ends of the two resistors is equal and the current is not equal
Of course, equal series current equal parallel they have equal voltage
U = U1 = U2 in equal series circuit
It's the same, but the voltage is different
VB topic: input triangle trilateral programming area
I made it up by myself, but it seems to be wrong. Prawn, help me to have a look (I used the cosine theorem)
Private Sub Command1_ Click()
Dim x As Double
A = InputBox ("please input the first side of triangle")
B = InputBox ("please input the second side of triangle")
C = InputBox ("please input the third side of triangle")
If a
Private Sub Command1_ Click()
Dim a#, b#, c#, p#
Me.AutoRedraw = True
a = 3: b = 4: c = 5
Do
A = Val (InputBox ("please input the first edge of triangle", "input", a))
B = Val (InputBox ("please input the second edge of triangle", "input", b))
C = Val (InputBox ("please input the third edge of triangle", "input", c))
If a a Then
P = (a + B + C) / 2's = √ [P (P - a) (P - b) (P - C)] (Helen formula) (P = (a + B + C) / 2))
Print "area:; (p * (P - a) * (P - b) * (P - C)) ^ 0.5
Exit Sub
Else
Msgbox "the data you input can't form triangle!", vbquestion + vbokonly, "please check the input"
End If
Loop
End Sub
In the arithmetic sequence {an}, if A1 = 35, d = - 2, Sn = 0, then n = ()
A. 33B. 20C. 35D. 36
∵ {an} is an arithmetic sequence, A1 = 35, d = - 2, ∵ Sn = Na1 + n (n − 1) 2D = 35n + n (n − 1) 2 × (- 2) = - N2 + 36N, ∵ Sn = 0, ∵ - N2 + 36N = 0, the solution is n = 36 or n = 0 (rounding off), so the answer is 36
Conversion of all primary school units (the more specific the better)
1 ton = 1000 kg 1 kg = 1000 g (weight unit) 1 km = 1000 m 1 m = 10 decimeter 1 decimeter = 10 cm 1 cm = 10 mm (length unit) 1 square kilometer = 100 hectare 1 hectare = 10000 square meter 1 square meter = 100 square decimeter 1 square decimeter = 100 square centimeter 1 square centimeter = 100 square
1kg = 1000g, 1t = 1000kg
1 m = 10 decimeters = 100 cm = 1000 mm, 1 km = 1000 m
1 square meter = 100 square decimeter = 10000 square centimeter = 1000000 square millimeter
1 cubic meter = 1000 cubic decimeter = 1000000 cubic centimeter = 100000000 cubic millimeter
1 hour = 60 minutes
1 minute = 60 seconds