The fourth question on page 200 of mathematics sixth grade

The fourth question on page 200 of mathematics sixth grade

NO NO NO !

All the answers to the sixth grade mathematics course

Rely on their own efforts, do not think about the answer, I used to be like this

How many pounds is 100 Jin

Conversion of weights and measures
1 lb = 0.45359237 kg, so 100 kg = 50 kg is about 110.23113109 lb

If 2A + 3B = - 1, then 3-4a-6b=

During the construction, a lamp needs to be connected temporarily. The power supply is far away from the construction site, and the wire used is long. When the incandescent lamp marked with "220 V & nbsp; 200 W" is connected, it is found that the lamp can not light normally. The measurement shows that the voltage at both ends of the lamp is 200 V, and the power supply voltage is stable and equal to 220 v. set the filament resistance unchanged, and the calculation result remains integer? (2) What is the voltage at both ends of the incandescent lamp marked "220 V & nbsp; 40 W"?

(1) The resistance of "220 V & nbsp; 200 W" incandescent lamp: RL = ul2pl = (220 V) 2200 w = 242 Ω; ∵ the wire is connected in series with the bulb, ∵ the voltage at both ends of the wire u line = U-U lamp = 220 v-200 v = 20 V, ∵ the current at all parts of the series circuit is equal, ∵ u line r line = u lamp r lamp, that is, 20vr line = 200 V242 Ω, the solution is: r line = 24.2 Ω≈ 24 Ω; (2) "220 V & nbsp; 200 W" incandescent lamp; The total resistance in the circuit: RL1 = ul12pl1 = (220V) 240W = 1210 Ω, the wire is connected in series with the bulb, the total resistance in the circuit: R total = R wire + R lamp 1 = 1210 Ω + 24 Ω = 1234 Ω, the voltage at both ends of the bulb: u lamp 1 = ur total × r lamp 1 = 220v1234 Ω × 1210 Ω ≈ 216v

It is known that the two roots of the quadratic equation (m-2) x & sup2; + 3mx + 1 = 0 belong to (- 1,0) and (0,2) respectively, and the value range of M is obtained

Try to combine graphics
Then list the inequalities according to the relationship in the graph

In the following situations, the energy conversion process is
A high jumper
A car going uphill
A plane on the road
Parachutists falling at a constant speed
What's more, do solar cells convert light energy into chemical energy or electric energy?

"-" means conversion, from left to right
1. Chemical energy kinetic energy gravitational potential energy
2. Chemical energy internal energy kinetic energy gravitational potential energy
3. (gravitational potential kinetic energy) - internal energy
4. Gravitational potential energy internal energy
Solar cells convert light energy into electricity, solar batteries convert light energy into electricity and then into chemical energy for storage

When the horizontal spring vibrator moves to the balance position, put a piece of rubber paste on it. Will the vibration amplitude change next?

Change. The period should not change

A student connected a 18 ohm resistance wire to the power supply, and the heat generated in 3 minutes was 1440 joules. When he connected a 6 ohm resistance wire to the power supply, how much heat was generated in 2 minutes?

Divide the square of the source potential by the resistance, and then multiply it by 160 seconds. The obtained value is the Joule number. List this equation to get the value of the source potential. List the same equation, and add new data to get the new Joule energy

What is the indication of the spring scale when it receives 5N force on the left and 7n force on the right

The indication of the spring scale is 5N. Through the force analysis, we can know how much force you give a spring scale hanging on the wall, and how much force its reaction force is. So under normal circumstances, you give it a 6N force, the indication of the spring scale is 6N, and the force given by the wall is 6N, because the spring scale is static