It's not my problem. They just do it

There are pens, erasers, rulers and other learning tools on the desk
(because the blackboard eraser is not a learning tool)

RELATED INFORMATIONS

1. If the gravity of the eraser is known to be 1.5n, the attraction between the eraser and the blackboard is constant 4N. When a thrust of 0.5N is applied to the eraser, the eraser can slide along the blackboard surface at a constant speed. If the eraser is to slide along the blackboard surface at a constant speed, a vertical upward force should be applied. The force is 0.5N___ ___ N．
2. The Chinese teacher went to the blackboard to wipe the blackboard, but he couldn't find it. The teacher asked: who knows where the eraser is? No one answered In the second Chinese class in the morning, the blackboard was full. The Chinese teacher went to the blackboard to wipe the blackboard, but he couldn't find it. The teacher asked: who knows where the eraser is? No one answered "Have the students on duty cleaned the blackboard after the first class?" "Yes, it's on the slot of the blackboard after cleaning," the student on duty replied "So who moved again?" the teacher asked No one answered. Some of the students were laughing, some of them were elated, and their eyes glanced at the top of the blackboard from time to time. Suddenly, the teacher understood everything. Someone was playing a prank and hid the blackboard eraser \If you are the teacher, how will you deal with this incident?
3. According to the uncertainty transfer formula of indirect measurement, which physical quantity has the greatest influence on the acceleration of gravity is analyzed Simple pendulum method. Need to give reasons
4. What is the unit of "ω" in the formula of alternating current e = NBS ω sin ω t? Is the unit of "ω" rad / S? Then why do some students say that they have to multiply it by a 2 π when doing the problem? For example: ω = 200 rad / s, do they need to change it into ω = 400 π rad / s when doing the problem?
5. As shown in the figure, a circular coil with a radius of R = 10cm has a total of 100 turns and rotates uniformly at a speed of n = 600r / min around the central axis OO 'perpendicular to the direction of the magnetic field in a uniform magnetic field with magnetic induction B = 5 / π 2 & nbsp; t, The timing starts when the coil turns to the neutral plane. (1) write out the instantaneous value expression of the alternating electromotive force generated in the coil. (2) calculate the instantaneous value of the electromotive force when the coil passes 1 / 60s from the position shown in the figure. (3) calculate the average value of the electromotive force when the coil passes 1 / 60s from the position shown in the figure;
6. The derivation of the alternating current formula e = 2blvsinwt = bswsinwt in senior two physics,
7. How is the maximum value of alternating current EM = NBS ω derived?
8. Derivation of several effective value calculation formulas of alternating current Sinusoidal alternating current U = um / √ 2, Sinusoidal half wave alternating current U = um / 2, Sinusoidal unidirectional pulsating current U = um / √ 2, Rectangular pulsating current U = √ (T / T) um, Asymmetric alternating current √ (1 / 2 * (U1 ^ 2 + U2 ^ 2))
9. On the formula of alternating current What is the meaning of sin ω t in the formula of alternating current e = e (m) sin ω t? Is it sin ω * t or sin ω t?
10. On the homeostasis expression of alternating current When to use EM = coswt, when to use EM = sinwt?
11. Among the following four physical quantities, the one with both size and direction is () (1) mass; (2) gravity; (3) force; (4) length A. （1）（2）B. （2）（3）C. （1）（3）D. （1）（4）
12. The physics problem is how to use the spring dynamometer to measure the buoyancy. It seems that there is density. I'll ask the teacher this afternoon. Let's first think about the specific process Thank you The following two I asked the teacher how to use the spring dynamometer to measure the buoyancy and then measure the density of the object
13. When studying pressure in physics, sometimes the solid pressure can be calculated by P = pGH (P stands for density). The teacher said that there are seven conditions. Which ones are they
14. Use a balance, two beakers, (no measuring cylinder) to measure the density of small stones The teacher talked about it before, but I forgot. It's not filling one beaker with water, then putting stones in it, and spilling water into another beaker. That's very simple. I know. What I asked is another method, not filling the beaker with water and putting stones in it
15. Teacher's Day is coming, I want to write some blessings to 8 teachers I want to write some blessing words to teachers of 8 subjects Each subject's blessing should be related to the subject's knowledge: for example, mathematics with knowledge, English with English Example: Mathematics (teacher's Day is coming, I wish you happy 365 days a year, 8760 hours, 5256000 minutes, 3153600 seconds) with numbers!
16. Is physics, mathematics and chemistry a teacher?
17. Can a chemistry teacher teach physics?
18. Write the poems of the teacher and the students
19. Poems about reluctant to part with friends "Hand in hand, we walked silently on the way to the railway station, speechless to each other. Dear friends who have been together for three years, how can we be willing to be separated in an instant."!
20. Write a poem about praising the teacher To write their own, can not be found on the Internet (to find not to give points) fast bonus, tonight