What are the physics formulas learned in junior high school?

Pressure———1 Pressure = Pressure Stress Area; 2. Uniform cylinder pressure on the horizontal support surface = density xgx height; Liquid pressure = density x gx vertical depth.

Buoyancy ——— buoyancy = weight of discharging liquid = density xgxv row.

Voltage———U=IR

Current ——— i=q t=u r=p u

Resistance——— r=u i

Electrical work———w=uit

Electrical power——— p=ui=u2 r=i 2r——— w=uit=uq

calorific ——— electric q=i 2rt; In heat transfer, the heat absorption and release q=cm (t-t0) and the specific heat ——— c=q m (t-t0).

work———w=fs; w=pt

Power——— p=w t=fv

Mechanical efficiency ——— mechanical efficiency = useful work Total work = gh fs = g nf (n is the number of segments of the rope on the movable pulley) = g (g + g wheel).

All the formulas for Grade 9 Physics are as follows:1. W i2rt u2t r (pure resistance formula).

r＝1/r1＋1/r2 [ r＝r1r2/(r1＋r2)]。

3. Q uit pt uq power u2t r (pure resistance formula).

4. Density calculation formula: =m v.

5. The formula for calculating solid pressure: P=F S, F represents pressure, unit ns represents area, unit M2P represents pressure, unit Pascal (Pa).

v (speed) = s (distance) t (time).

h (echo ranging) = v t 2

m (mass) = (density) v (volume).

m (individual mass) = m (total mass) n (number).

g (gravity) = m (mass) g (gravitational constant).

p (pressure) = f (force exerted) s (contact area).

p (liquid pressure) = (liquid density) g (gravitational constant) h (depth) f (buoyancy) = g (discharging water gravity) = (liquid density) v (discharging liquid volume) g (gravitational constant).

w (work) = f (magnitude of force) s (distance traveled).

w (work) = p (power) t (time).

p (power) = f (power) v (speed).

f (power) l (power arm) = f (resistance) l (resistance arm) (efficiency) = w (useful work) w (total work).