Chemistry
N_2+H_2==NH3 ▲H=-x (release heat) is a reversable reaction. And how to increase the volume of obtained NH3 when the reaction is chemically equilibrium (For Ammonia)?
A. Increase the temperature (Tips, ↑temperature=→Endothermic reaction)
B. Add more Argon (Tips, argon is unreactive)
C. Decrease the volume (Tips, volume has to do with pressure)
D. Add more Ammonia to obtain more (Tips, Concentration of gases affect the outcome)
C
Equation for hooke's law?
F=kx
state the equation connecting initial velocity, final velocity, acceleration and displacement
v^2-u^2=2as
state the equation relating power, resistance and current
P=I^2*R
方言形成的两个原因
地理(交通);历史;政治
N_2+H_2==NH3 ▲H=-x (release heat) is a reversable reaction. And how to increase the volume of obtained NH3 when the reaction is chemically equilibrium (For Ammonia)?
A. Increase the temperature (Tips, ↑temperature=→Endothermic reaction)
B. Add more Argon (Tips, argon is unreactive)
C. Decrease the volume (Tips, volume has to do with pressure)
D. Add more Ammonia to obtain more (Tips, Concentration of gases affect the outcome)
state three forms of thermal energy transfer
Conduction, convection and radiation
an object falls from 125m cliff, when will it strike the ground
5 sec after
Explain what does a relay switch do?
uses smaller current to control a larger current; Isolation function.
[Economics] State 5 factors of supply.
Production cost, subsidy, tax, technology changes, number of sellers, natural factors, future expection.(5 of 7)
Which of them isn’t an endothermic(吸热) reaction? A.Nitrogen and hydrogen react
B.Potassium permanganate reacts to form oxygen
C.Carbonic acid becomes water and carbon dioxide
D.Hydrogen peroxide forms hydrogen and oxygen
A
why is the heating element in the kettle located at the bottom instead of the sides?
Convection [Correct as long as convection is mentioned]
the initial velocity of an object is (25,40) in m/s, 5 seconds after the velocity is (5,70) in m/s what is the avg. acceleration in m/s^2?
(-4,6)
A 1 ohm lamp and a 2 ohm lamp is connected in series to the battery, which lamp is brighter? and why?
2 ohm lamp[1], P=I^2*R, current is the same in series circuit[1], hence bigger resistance results in more power[2].
State one point where AP Physics is different from IG Physics.
acceleration, range, etc
Which is safer for humans? A.Nitric acid B.Sodium hydroxide C.Hydro-sulfuric acid D.Acetic acid
D
A circular pipe filled with liquid has an inlet radius of 10 and an outlet radius of 5. At this time, the inlet liquid surface is suffering 100N force, and what is the force on the outlet liquid surface?(ignore friction and resistance)
100N(force does not change, the only thing changes is the pressure)
An object is launched with initial velocity of V m/s at 30 degree above horizon, the horizontal range of this projectile is R, then the same object is launched again with initial velocity of 3V m/s at 30 degrees above horizon, what is the horizontal range?(express in terms of R)
9R
State 2 properties(function) of capacitor
Store charge;allows AC to pass through but not DC;reduce voltage fluctuates(keep stable);(and more)
Convert 16(hexadecimal) to Binary.(with paper and pen only!!!)
10110
Why do ionic compounds that contain metals from Group 1 won't react with OH- and H+ anymore when it's in water?And why do metals like copper will form precipate
Because ionic compound in the Group 1 like NaOH will be separated by water completely and ions won't react ions of water anymore because ionic compound contain metals from Group 1 will be separated again. And trasition metals like Cu can react with ions and form precipate Cu(OH)2 because a metal hydroxide will always be insoluble except metals from Group 1.
(Free Body diagram)
Answer
state the equation for X range in a projectile;
R=(u^2*sin(2*angle))/g
An oscilloscope is connected to an AC generater. What kind of wave can be observed? and why?
Sine wave[300], the coil rotates and the voltage varies with the position of the coil.[200]
state one country which didn't want to join 轴心国 in WWII.
Soviet Union 南斯拉夫 Romania Spain...(and more)