1. 16 (2 points for each question)
1 .b.2.d.3. A.4.c.5.b.6.c.7.b.8. A.
2.26 points (9~ 14 1 point, 2 points for 15~ 16).
9. 1.5; Series connection; Electricity. 10. Newton; External force; Force. 1 1. Friction; Conditions for the balance of two forces; Internal combustion. 12. greater than; a； Increase. 13.4.9; 19.6; there will be no changes. 14.0.5; 30; 12。 15.a、a 1； Right or left. 16.① When the solenoid is energized, there is a magnetic field inside the solenoid. ② When the current direction in the solenoid changes, the magnetic field direction in the solenoid changes.
Three. (3 points for each question)
17. 2 points for reflected light; The reflection angle and its degree are 1 point.
18. The magnitude of the force is1; Direction 1 min; Action points 1 point.
twenty four past four
19.
(4 points) ①△ T = 80℃-30℃ = 50℃ 1 min.
②Q suction = cm△ t 1.
= 0.45× 103 J/(kg？ ℃) × 2kg× 50℃ 1 min
= 4.5× 104 jiao 1 min
20.
(4 points) ① v = s/t 1 min.
= 1.2m/ sec = 0.6m/ sec 1 min
② w = fs 1。
= 5 N × 1.2m = 6 angle 1 min
2 1.
(8 points) ① P water = rho water gh water 1 min.
= 1.0× 103kg/m 3×9.8n/kg×0. 1m = 980 Pa 1min。
②V alcohol = M alcohol/ρ alcohol 1.
= 1.6kg/(0.8× 103kg/m3)= 2× 10？ 3 m 3 1 min
H alcohol = V alcohol /SB = 2× 10? 3m 3/( 1× 10-2 m2)= 0.2m 1。
③A 1
P water = p alcohol ρ water gh water = ρ alcohol gh alcohol
1.0× 103 kg/m 3×h water? = 0.8×103kg/m3× 0.2m.
H water? = 0. 16m 1 point
V metal = △ V water = SA △ H water = 2×10-2m2× (0.16m-0.1m).
= 1.2× 10? 3 m 3 1 min
22.
(8 points) ① R2 = U2/I 1 min.
= 4.5v/0. 1 5a = 30h1min.
② W2 = U2IT 1 min
= 4.5v× 0.15a×10s = 6.75J 1 min.
③ Can score 1.
The resistance R 1 is a constant resistance, (u-U2)/I = (u-U2? )/me?
(U-4.5V)/0. 15A =(U-2.0V)/0.4a 1。
U = 6V 1 min
R1= (u-U2)/I = (6v-4.5v)/0.15a =10 our1min.
Note: In the calculation, if the relevant units are misspelled or omitted, the total score is 1.
V. 18, 23 ~ 24 (8 points)
23. Pallet balance; Quality; Positive; 4.5。
24. Glass plate; Vertical; Small flowers; Exploratory experiments need to measure multiple sets of data to make the experimental results more comprehensive. Xiaohua did three experiments during the exploration, which met the requirements of physical experiments.
Note: per grid 1 min.
25.(5 points)
1 omitted. ( 1)
②②20ω2A( 1+0)； 2.5( 1); 0.2( 1); 0.5( 1).
26.
(5 points) ① The water pressure at the bottom of the tank increases with the increase of the number of added circular plates. ( 1)
(2) (a) According to the data of pressure change in Table 1 or Table 2 and related conditions, a preliminary conclusion can be drawn: when the cylinder floats on the water (or sinks to the bottom), the liquid pressure at the bottom of the tank will increase by the same amount for each additional round plate. (2 points) (b) According to the data of pressure changes in Table 1 and Table 2 and related conditions, it can be concluded that the liquid pressure at the bottom of the tank increases when the cylinder floats on the water surface than when it sinks to the bottom. (2 points)