Recent content by Rockdog

I've included a picture. Two charges Qc and -Qc(Qc = 4 µC) are fixed on the x-axis at x = -7 cm and x = 7 cm, respectively. A third charge Qb = 5 µC is fixed at the origin. A particle with charge q = 0.3 µC and mass m = 5 g is placed on the y-axis at y = 14 cm and released. There is no...

I've included a picture. Two charges Qc and -Qc(Qc = 4 µC) are fixed on the x-axis at x = -7 cm and x = 7 cm, respectively. A third charge Qb = 5 µC is fixed at the origin. A particle with charge q = 0.3 µC and mass m = 5 g is placed on the y-axis at y = 14 cm and released. There is no...

During a cold Chicago winter, a steady thermodynamic state has been reached in a small pond with a layer of ice on the top. The air directly above the pond is at -7 oC and the ground at the bottom of the pond is held at 2 oC. The pond holds a total of 342.1 m3 of water and has a relatively...

The transverse displacement of a harmonic wave on a stretched rope is y = 0.03 cos(2.7 t - 2.9 x), where x and y are in meters and t is in seconds. A 5 meter length of this rope has a mass of 1.5 kg. ************** a) What is tension in rope? b) At time t = 0, consider a 1/2 wavelength long...

Ok, maybe I'm missing something obvious. When the pendulum is directly vertical, isn't h going to be same thing as the length of the string?

Ok, so use conservation of energy. It starts off with potential energy, and then it gets converted to kinetic energy. So it be mgh=.5mv^2 mass cancel out so I'm left with gh=.5v^2 h=.805 m or h=.805m/cos 10 and I get v=3.972m/s Then use a= V^2/R ? Is this the right approach?

Ok. R=2*pi sqrt(L/g) L=.805m I know that centripetal acceleration equals a = V^2/R or can be rewritten as a= w^2*R w equals 2*pi/T w=3.49 T is the period or 1.8 seconds. so a=3.49^2*.805 =>9.80 m/sec^2 Does that appear right? The computer says no, but all my calculations say yes.

A simple pendulum of mass 15 kg with a period of 1.8 sec is displaced an angle of 10 degrees from the vertical. What would its acceleration be in the vertical (y) direction as it reachs the lowest point on its swing? ********** Ok, I understand that it is a simple pendulum, but how do I...

See the picture. 1 atm = 101300 Pa = 101300 N/m2 density of water = 1000 kg/m3 The tube is filled with water. A1 = 0.05m^2 and A2 = 0.08m^2. Two pistons apply different forces to the water in the tube so that the water in the right side of the tube is a height h = 0.43m above the height...

Sorry, can you explain something first. First part, I figured out the density value to calculate the mass of the portion of the sphere inside radius 1.1 m. Now you say treat it as a concentrated mass at the center of the sphere. Ok, but I mean, what do I do with it in terms of calculation...

A solid sphere has a uniform density, a mass of 17 kg and a radius of 2.2 m. ============= a) What is the force due to gravity from the sphere on a very small object of mass 21 grams located 1.1 m from its center? b) What is the force due to gravity from the sphere on a very small object...

Yup. Ok. You know that v=vo+at well, v=w*r and w=alpha*t substitute all that into above equation, and solve for time. Same idea for part d, just use different vo.

I'd say, yes. What do you do if you found out that your mom is really a man?

I've included a pic. A refrigerator is approximately a uniform parallelepiped h = 8 ft tall, w = 3 ft wide, and d = 2 ft deep. It sits upright on a truck with its 3 ft dimension in the direction of travel. Assume that the refrigerator cannot slide on the truck and that its mass is 110 kg. For...

A biology student rides her bike around a corner of radius 30 meter at a steady speed of 8.1 m/sec. The combined mass of the student and the bike is 89 kg. The coefficient of static friction between the bike and the road is ìs = 0.32. a) If she is not skidding, what is the magnitude of the...