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What does △ P mean in physics
Depending on the situation, P has many meanings, but it depends on the electric power
Delta in physics refers to the amount of change, so combined with it, it should be the amount of electric power change
That is to say, it is equivalent to △ P = P1-P2
Lever principle and formula
Lever principle is also called "lever balance condition". In order to balance the lever, the magnitude of the two forces (force point, fulcrum and resistance point) acting on the lever is inversely proportional to their force arm. Power × power arm = resistance × resistance arm, which is expressed by the algebraic formula F1 · L1 = F2 · L2. In the formula, F1 represents power, L1 represents power arm, F2 represents
Why is leverage the easiest?
Use a 1.2m long shoulder pole to carry water. Two buckets weigh 200N and 400N respectively. Please calculate and explain where you feel most relaxed when you put your shoulder on the shoulder pole
Consider the two barrels and the shoulder pole as a system. The shoulder should be placed at the center of gravity of the system
The center of gravity of the system is the fulcrum, which is supported by the shoulder. They are balanced
Set your shoulders away from the 200 N barrel X and balance the system
Then G1 * x = G2 * (l-x),
Where G1 = 200N, G2 = 400N, l = 1.2m
So 200 * x = 400 * (1.2-x)
X = 0.8m
The pressure on the shoulder is f = G1 + G2 = 200 + 400 = 600 n
[please click the [adopt as satisfactory answer] button in time [
When the lever is balanced, to minimize the force acting at a certain point, why is the arm of force the longest?
Because the lever balance condition is: power x power arm = resistance x resistance arm, in the case of a certain resistance and resistance arm, the longer the power arm, the smaller the force used, so to make the force acting at a certain point minimum, the force arm should be the longest
1、 Fill in the blanks:
1. When sweeping the floor with a broom, the broom becomes a lever, which can be saved in use
2. Use the lever with 120cm power arm and 30cm resistance arm to pry a 2800N large stone block, and the power acting on the lever should be at least n
3. If the resistance acting on the lever is 1200n, the ratio of the power arm to the resistance arm is known to be 5:1, and the power used to balance the lever is n
4. If 500N downward force is applied on the pulley block, the goods weighing 2500n can be lifted up at a uniform speed (excluding friction and pulley weight), then a pulley block and a fixed pulley are needed to form a pulley block
5. When a person carries a load, the length of the shoulder pole is 1.2m. If 700n weight is hung at the front end and 500N weight is hung at the back end, the shoulder should be cm away from the front end to balance the load. If the weight at both ends is reduced by 100N, the shoulder should move cm to the end
(fill in the blank, note: please write the title label)
1. Strenuous distance
2700
3,240
4,1---3
5,70-----2
Second grade physics (leverage)
A shoulder pole is 1.5 meters long, with a weight of 200 N in the front and 250 n in the back. How far should the shoulder be from the back of the shoulder pole to keep the balance?
Let L = L1 + L2 = 1.5, N1 = 200, N2 = 250
N1*L1=N2*L2
200*（L-L2）=250*L2
The solution is: L2 = 2 / 3M
About leverage,
Two solid iron blocks of different mass are hung on both ends of the lever, and the fulcrum is selected to balance them. If two iron blocks are immersed in water at the same time, the lever will be stable
A. Still in balance
B. Hang a heavy iron block and sink at one end
C. Hang a small iron block and sink at one end
D. Can't judge
The lever is low on the left and high on the right. Where should I adjust the balance nut at the right end of the lever? What about the one on the left
Adjust to the right, because the right side is high, it means the right side is light, so adjust the nut to the right
If two hook codes are hung on the third grid on the left side of the lever ruler, in order to balance the lever ruler, several hook codes should be hung on the right side of the lever ruler? (be more detailed!)
According to the lever balance condition f1l1 = f2l2, it is obtained that
2 * 3 = 1 * 6 or 2 * 3 or 3 * 2 or 6 * 1
So you can hang six hook codes in the first grid, three in the second grid, two in the third grid, and one in the sixth grid
When the lever is balanced, the weight on the left multiplied by the distance equals the weight on the right multiplied by the distance
Because of the special design, it should be stable balance, that is, it will return to the balance position when there is a slight deviation
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