If an object is floating in water does that mean that the weight is zero?

The difference between two numbers is 15. when twice the smaller number is subtracted from three times the larger number, the difference is 58.what is the larger number?

Which change would make the diagram correct?

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?