Would sound travel faster through a gas that is 90% nitrogen and 10% helium or through a gas that is 90% helium and 10% gas

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?

When you hold a rectangular object, how does the area of the side that is resting on your hand affect the pressure and the force that the object exerts?

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?