5. Bill has a mass of 70 kg and is running. He collides with Ethel, who is sitting in a chair with wheels. Ethel's mass is 50 kg. Bill falls into Ethel's lap and they both go rolling at 5 m/s. How
fast was Bill running before the collision?

Why do different substances have diffrent properties

Thermal radiation gets its name because

You have a resistor and a capacitor of unknown values. first, you charge the capacitor and discharge it through the resistor. by monitoring the capacitor voltage on an oscilloscope, you see that the voltage decays to half its initial value in 3.00 ms . you then use the resistor and capacitor to make a low-pass filter. what is the crossover frequency fc?