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初中物理公式汇总

2020-03-11 15:18:05来源:七考网综合

很多同学都说初中物理很难,其实物理和其他学科一样,其他学科能学好,物理也一定能学好。下面是小编总结的初中物理公式知识点,相信你的物理成绩一定能够得到提高的。

一、速度公式

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" width="574" />

火车过桥(洞)时通过的路程s=L桥+L车

声音在空气中的传播速度为340m/s

光在空气中的传播速度为3×108m/s

二、密度公式

(ρ水=1.0×103kg/m3)

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" width="575" />

冰与水之间状态发生变化时m水=m冰 ρ水>ρ冰 v水

同一个容器装满不同的液体时,不同液体的体积相等,密度大的质量大

空心球空心部分体积V空=V总-V实

三、重力公式

G=mg (通常g取10N/kg,题目未交待时g取9.8N/kg)

同一物体 G月=1/6G地

m月=m地

四、杠杆平衡条件公式

F1l1=F2l2

F1 /F2=l2/l1

五、动滑轮公式

不计绳重和摩擦时F=1/2(G动+G物)s=2h

六、滑轮组公式

不计绳重和摩擦时F=1/n(G动+G物)s=nh

七、压强公式(普适)

P=F/S

固体平放时F=G=mg

S的国际主单位是m2 1m2=102dm2=104cm2=106mm2

八、液体压强公式

P=ρgh

液体压力公式F=PS=ρghS

规则物体(正方体、长方体、圆柱体)公式通用

九、浮力公式

(1)F浮=F’-F (压力差法)

(2)F浮=G-F (视重法)

(3)F浮=G (漂浮、悬浮法)

(4)阿基米德原理:F浮=G排=ρ液gV排 (排水法)

十、功的公式

W=FS

把物体举高时W=GhW=Pt

十一、功率公式

P=W/t

P=W/t=Fs/t=Fv(v=P/F)

十二、有用功公式

举高W有=Gh

水平W有=Fs

W有=W总-W额

十三、总功公式

W总=FS (S=nh)

W总=W有/η

W总= W有+W额

W总=P总t

十四、机械效率公式

η=W有/W总 η=P有/ P总

(在滑轮组中η=G/Fn)

(1)η=G/ nF(竖直方向)

(2)η=G/(G+G动) (竖直方向不计摩擦)

(3)η=f / nF (水平方向)

十五、热学公式

C水=4.2×103J/(Kg·℃)

1.吸热:Q吸=Cm(t-t0)=CmΔt

2.放热:Q放=Cm(t0-t)=CmΔt

3.热值:q=Q/m

4.炉子和热机的效率: η=Q有效利用/Q燃料

5.热平衡方程:Q放=Q吸

6.热力学温度:T=t+273K

7.燃料燃烧放热公式Q吸=mq或Q吸=Vq(适用于天然气等)

电学部分

1.电流强度:

I=Q电量/t

2.电阻:

R=ρL/S

3.欧姆定律:

I=U/R

4.焦耳定律:

(1)Q=I2Rt普适公式)

(2)Q=UIt=Pt=UQ电量=U2t/R (纯电阻公式)

5.串联电路:

(1)I=I1=I2

(2)U=U1+U2

(3)R=R1+R2

(5)W=UIt=Pt=UQ (普适公式)

(6)W=I2Rt=U2t/R (纯电阻公式)

(7)U1/U2=R1/R2 (分压公式)

(8)P1/P2=R1/R2

6.并联电路:

(1)I=I1+I2

(2)U=U1=U2

(3)1/R=1/R1+1/R2 [ R=R1R2/(R1+R2)]

(4)I1/I2=R2/R1(分流公式)

(5)P1/P2=R2/R1

7.定值电阻:

(1)I1/I2=U1/U2

(2)P1/P2=I12/I22

(3)P1/P2=U12/U22

8.电功:

(1)W=UIt=Pt=UQ (普适公式)

(2)W=I2Rt=U2t/R (纯电阻公式)

9.电功率:

(1)P=W/t=UI (普适公式)

(2)P=I2R=U2/R (纯电阻公式)

常用物理量

1光速:C=3×108m/s (真空中)

2.声速:V=340m/s (15℃)

3.人耳区分回声:≥0.1s

4.重力加速度:g=9.8N/kg≈10N/kg

5.标准大气压值:760毫米水银柱高=1.01×105Pa

6.水的密度:ρ=1.0×103kg/m3

7.水的凝固点:0℃

8.水的沸点:100℃

9.水的比热容:C=4.2×103J/(kg•℃)

10.元电荷:e=1.6×10-19C

11.一节干电池电压:1.5V

12.一节铅蓄电池电压:2V

13.对于人体的安全电压:≤36V(不高于36V)

14.动力电路的电压:380V

15.家庭电路电压:220V

16.单位换算:

(1)1m/s=3.6km/h

(2)1g/cm3 =103kg/m3

(3)1kw•h=3.6×106J

相关内容: 初中物理 初中物理公式 速度公式

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