A frictionless spring with a 4-kg mass can be held stretched 0.2 meters beyond its natural length by a force of 30 newtons. If the spring begins at its equilibrium position, but a push gives it an initial velocity of 1 m/sec, find the position of the mass after t seconds.

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

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 2.70 miss . you then use the resistor and capacitor to make a low-pass filter. what is the crossover frequency fc?