Physics Current Electricity Level: Misc Level
How is the movement of electricity through air different from its movement through a copper wire?
Physics Modern Physics Level: Misc Level
Nearly all the mass of an atom is concentrated in its nucleus. Where is its charge located?
Physics Current Electricity Level: Misc Level
Electricity was once thought to be a weightless fluid, an excess of which was" positive"and a deficiency of which was "negative".What phenomena can this hypothesis still explain ? What phenomena can it not explain?
Physics Kinematics Level: Misc Level
A child on a sled on a frictionless snowy hill of height 30 m has an initial potential energy of 9000 N. The child slides down the hill. When she reaches a height of 10 m what is her kinetic energy
Physics Circular Motion Level: Misc Level
A child on a swing has a speed of 6.9 m /s at the lowest point of the arc. How high will the swing be at the high point (taking the lowest point as height zero )?
Physics Work,Power & Energy Level: Misc Level
A dart gun shoots a small dart using a compressed spring .If I shoot a 0. 1 kg dart with a speed of 8 m /s using the gun, how much potential energy did I have to store in the spring to accomplish this feat? ( Assume that this is a conservative system ).
Physics Force & Laws Of Motion Level: Misc Level
Two people on ice skates stand face -to-face on the ice and then push each other away. Their masses are 60 kg and 90 kg If immmediately afterwards the person with mass 60kg is moving at a speed of 1 m /s, how fast is the 90 kg person moving?
Physics Force & Laws Of Motion Level: Misc Level
A 40 kg boy on roller skates moves with a speed of 4 m /s.He runs into a 30 kg girl on skates who is initially not moving. Assuming they cling together, what is their speed right after the collision?
Physics Force & Laws Of Motion Level: Misc Level
A small rocket loses mass at a rate of Dm /Dt=8 kg /s through its rocket engine. If the speed of the exhaust gas coming out the back of the rocket is 600 m /s, what is the force on the rocket? Hint: Use Newton s second law in its alternative from F =D (mv /Dt.
Physics Force & Laws Of Motion Level: Misc Level
Carts A and B stick together whenever they collide. The mass of cart A is twice that of B.How could you roll the two carts together ( i. e. at what relative speeds ) so that they would be stopped after the collision? ( Assume there is no friction )
A) You would roll them at same speed towards each other.
B) You would roll them towards each other.with B having twice the speed of A.
C) You would roll them towards each other, with A having twice the speed of B.
D) You would keep A at rest and crash B into it.
Physics Properties Of Matter Level: Misc Level
Estimate the freezing point of 150 cc of water sweetened with 7.5 g of sucrose.
Chemistry Physical Chemistry Level: Misc Level
The vapour pressure of a sample of benzene is 53.0 k P a at 60.6 degrees C, but it fell to 51. 2 k P a when 0. 125 g of an organic compound was dissolved in 5.00 g of the solvent. Calculate the molar mass of the compound.
Chemistry Physical Chemistry Level: Misc Level
The rise in atmospheric carbon dioxide results in higher concentrations of dissolved carbon dioxide in natural waters. Use Henry s law and the following data to calculate solubility of CO2 in water at 25 degrees C when its partial pressure is a) 4.0 k P a b ) 100 k P a
Carbon dioxide Henry s law constant at 25 degrees C =2 .937 K H /k P a m3 /mol
Chemistry Physical Chemistry Level: Misc Level
Calculate the concentration of carbon dioxide in fat given that Henry s law constant is
8.6 x 10 to the 4 th Torr and the partial pressure of carbon dioxide is 55 k Pa.
Chemistry Physical Chemistry Level: Misc Level
At 300 K, the vapour pressure of dilute solution of H C I in liquid GeCI4 are as follows:
x (HCI ) 0.005 0.012 0.019
p /k Pa 32.0 76.9 121.8
Show that the solution obeys Henry s law in this range of mole fractions and calculate Henry s law constant at 300 K.
