A physics problem! Urgently need the process!

i=4 20=Because this is a series circuit (don't look at the voltmeter, wipe it off without affecting the circuit) the current is equal everywhere.

i= r=r1+r2=10+20=30 u=30*sliding to the midpoint means that the r2 resistance is half of the maximum at this point, so it is 10

3.The equal offset of the meter means that its exponents are equal, when p moves to the leftmost end, the resistance is zero, so at this time the two voltmeters measure the voltage of the same resistance r1, so the indication is equal, and the total resistance is r1 resistance 20

If you don't understand, ask me again o(o

It can be known that the sliding rheostat is 10 ohms when the midpoint is connected.

According to i=u r, the current is .

The total resistance is 10 ohms + 20 ohms = 30 ohms.

The total voltage is 30 ohms

When the slip access resistance is zero, the two meters are equal;

It is then discussed according to the range classification.

1) First of all, you have to figure out what the circuit looks like. First of all, remove all the voltmeter and ammeter, and you can see that this is a series circuit. Then according to the nature of the series circuit, it can be known that the current in the circuit is equal everywhere, so the number of the voltmeter V1 is 4V, and the resistance value of the resistance R1 is 20, and I = 4 divided by 20 = can be obtained, which is the number of the ammeter.

2) p is at the midpoint, and the current is known by (1), then the indicator of voltmeter v is u=4+10*

3) I won't write about the specific process of this question, think about it yourself, if the deviation angle of V1 and V is the same, that is, the readings of the two tables are the same, then think about it, what if the resistance of the sliding rheostat is zero? Then there is only the resistor R1 left in the circuit, think about it yourself, is this possible?

Looking at the type of question, you should go to junior high school, if you can't do this kind of problem, it seems that you have to work on physics!!

1）i=u/r=4/20=

The indication of the ammeter is:

2) u1 u2=r1 r2=20 10=2So, u2=2v

u=u1+u2=6v

The voltmeter V is indicated at 6V

1)i=u/r=20/4=

2)20+10=30 u=ir=30*

3) Probably, when the resistance of R is zero, R1 shares all the voltage, so that the voltage is 6V like the total voltage V.

1 m = p * v = 1000 kg cubic meter * cubic meter = 3 kg.

2 e = c * m * t = 1 joule * 3000 g * (100-20) = joules.

Q=P*TT=Q P=E 840 Watts = Seconds = Minutes.

3 p=u*i=u^2/r

r = u 2 p rated = (u * actual.

p actual = p rated * watts.

1. The density of water can be found to be 3 kg.

2. The heat absorbed by boiling water is Q=CM(T-To)=PThe time can be found in seconds.

3. Use p amount = U2 R to find the R pot, P real = u real 2 R pot can be found.

Let the resistance of the resistor be r

The total resistance after parallel connection r1 = r 2 = ohm.

The total resistance after series connection r2 = 2r = 4 * (r 2) = 2 * ohms.

Total resistance r=r1+r2=440+110=550 The intensity of the current passing through the two lamps is equal, both are.

i=u/r=220/550=

u1=ir1=

u2=u-u1=220-176=44v

1) The resistance value of the same resistance in parallel is half of the resistance, so one resistance is 5 ohms, and the series connection is the addition of the two, so the total resistance is 10 ohms.

2) Total resistance = r1 + r2 = 440 + 110 = 550 ohms.

The current is equal everywhere = 220 550 =

u1=i*r1=

u2=i*r2=

1 r+1 r=1 r, so the total r=5, so the total number of series r = 10 r=440+110=550

i=u/r=220/550=

u1=i1*r1=

u2=i2*r2=

1.The total resistance of two resistors with the same resistance value in parallel is in Ohms, what is the total resistance of them in series?

The formula for calculating the resistance value of the parallel resistance is equal to the product of the two resistors divided by the sum of the two resistors, the parallel connection of the same resistance value is equal to half of one of the resistances, and the total resistance of the two resistors with the same resistance value in the question is in Europe, then the resistance value of each resistance is 5 ohms, and the series connection is equal to the addition of the two resistors, so it is equal to 10 ohms.

2.If two lamps are connected in series in a 220V lighting circuit, if their resistors R1 and R2 are 440 and 110 respectively, find the total resistance of this circuit, through the current intensity of each lamp, and the voltage at both ends of each lamp.

The total resistance of this circuit is r1 + r1 = 440 + 110 = 550 (ohms); Since it is in series, the currents are equal, and the current is equal to the voltage divided by the total resistance i=220 550=; The voltage distributed to each lamp is proportional to the resistance, which is: 440*; 110*

1.It can be obtained according to the leverage balance condition.

G object * oc = g 砣 * od

m matter g*oc = m 砣 g*od

mObject* The mass of the object.

m = 6kg

2.When the scale is hung at B, the mass of the object is the largest, that is, the mass of the object at this time is the maximum weight of the scale.

g matter * oc = g 砣 * ob

m matter g*oc = m 砣 g*ob

mObject*The maximum weight is.

m = 10kg

1) Gravity: w=mgh= 4-2 3 joules according to the angle h=(2- 3) tension: Since it is a circular motion, the tension does not do work.

2) According to the kinetic energy theorem: w=ek=4-2 3 joules.

1 2 * square = 4-2 3 joules.

v=...3) F direction = f zhang - g = m * (v square 2) = square 2

120m/s？？Is it too large, the condition may be 120km h, if the condition is correct, the calculation is as follows: The reaction time is a uniform linear motion, x1 = 120*

The brake belongs to the uniform deceleration of the linear motion, a=f m=

The initial velocity is 120m s, and the final velocity is 0 a=-4m s2 Motion formula: The square of the end of v-the square of the beginning of v=2*a*x2

Solution-8*x2=0-14400 x2=1800m, total displacement=1860m

The motion process of the car is a uniform linear motion and a uniform deceleration linear motion.

120km/h=100/3 m/s

The distance of uniform linear motion is s1, and s1=100

The linear motion distance of uniform deceleration is S2, S2=V 2 (2A)=1250 9ms=S1+S2=100 6m+1250 9m=

f=μmg-->am=μg=1m/s^2 am=μg/3=1/3 m/s^2

Assuming the small block does not slide down.

When their velocity is equal, t=10 (1+1 3)=the block slides relative to the plank: swood-s-s=vt-1 2amt 2-a 2amt 2=>>

So the little things will slide down.

Let t slide down, then v0t-1 2(am+am)t 2= --10t-2 3t 2=

5t^2-75t+12=0 --t=

v=at=