Recent content by Koyuki

the reaction of H and F produces about 500 kj/mol of energy: how much energy is produced by the reaction of 2.0kg of H with 38 kg of F to produce 2 kmol of HF? The answer is 5.0x 10 to the exponent 5 kJ... but I'm not sure why... Please help! Thanks!

Hello. I'm having some trouble with this problem: A tuning fork is set into vibration above a vertical open tube filled w/ water. Water level is dropping slowly. As it does so, the air in the tube above the water level is heard to resonate w/ the tuning fork when the distance from the tube...

The problem is: "In an electrical circuit, the voltage, V volts, as a function of time, t minutes, is given by V = 12 - 9t + 2t^2. Determine the greatest and least values of voltage during the first 5 min. When do these values occur?" The answers given are exact. Least: 1.875 V @ 2.25 min...

This is probably horribly easy, but it's almost 1 AM so I'm going nutty trying to figure this one out. The questoni: "A 2000kg car is traveling at a constant 30m/s with the motor producing a force of 4000 N forward. Find the force of friction." I drew the diagram. Is acceleration 0...

More volume = more shock (force) absorbed? Like when your bee-hind hits an object, it doesn't hurt THAT bad because the more fat there cushions the impact. Your foot hitting the object will hurt more because there's less fat there. I'm doing this question too...btw, which class are you in?

Hey, PhysicsBeginner, by any chance do you go to school in Scarborough, Canada? I came here to ask about this same exact question that's in the booklet our teacher gave. edit: After reading your other posts, I think you go to the same school as I do! Haha, how cheap. edit2: Also, are his/her...