# Search results

1. ### Balancing redox reaction by half-reaction method

Homework Statement Balance the following equation by the half-reaction method. The reaction takes place in basic solution. Fe(OH)2(s) + O2(g) --> Fe(OH)3(s) The Attempt at a Solution All the other problems like this had 2 reactants and 2 products. What's confusing me about this problem is...
2. ### Difference between a kelvin and a celcius degree

Homework Statement I feel stupid posting this but I am completely lost. This is a problem on my Chemistry textbook's website, which gives immediate feedback on whether you are right or wrong, and I am just unable to get it right. The question: What is the difference between a kelvin and a...
3. ### Doppler Effect

Homework Statement A stationary observer at a crosswalk hears an ambulance siren with an apparent frequency of 480 Hz when the ambulance is approaching. After the ambulance passes the apparent frequency is only 420 Hz. Find the speed of the ambulance. Assume v = 343 m/s for the speed of sound...
4. ### Angular momentum

Homework Statement A uniform solid disk of mass m = 4.50 kg and radius R = 25.0 cm rotates at 7.00 rad/s about an axis perpendicular to the face of the disk. Calculate the magnitude of the angular momentum of the disk (a) when the axis of rotation passes through the center of the disk, and...
5. ### Finding speed using energy equations

Homework Statement Two masses are connected by a light string running over a frictionless pulley as shown below. The system is initially at rest and the incline is frictionless. If m1 = 10.0 kg, m2 = 8.00 kg and the incline makes a 30o angle from the horizontal, use energy methods to find the...
6. ### Finding distance with the conservation of energy equation

Homework Statement 3. A baseball (m = 0.150 kg) is thrown with an initial speed of 30.0 m/s at an angle of 37.0 degrees from the horizontal at y = 0 m. (a) Find the initial KE of the ball. (b) Use conservation of energy (not kinematic equations) to find the maximum height reached by the ball...
7. ### Force of a roller coaster track on a car

Homework Statement The roller coaster car shown below has a mass of 800 kg when fully loaded with passengers. (a) If the car has a speed of 25.0 m/s at point A, what force does the track exert on the car at that point. (b) If the car has a speed of 10.0 m/s at point B, what force does the track...
8. ### Force on two boxes attached by a string

Homework Statement Two blocks connected by a light string are being pulled to the right by a constant force of magnitude 30.0 N making an angle of 25o from the horizontal. The coefficient of kinetic friction between each block and the surface is 0.100. If m1 = 5.00 kg and m2 = 10.0 kg , (a)...
9. ### Tension of a string with a pulley

Homework Statement Two masses are connected by a string over a pulley as shown below. The incline is frictionless and makes a 50 degree angle from the horizontal. If m1 = 3.00 kg and m2 = 8.00 kg, find the tension in the string. Homework Equations F = ma The Attempt at a Solution I...