How is the resistor more useful for testing if the battery is dead?

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?

Acharged particle moves in a circular path in a uniform magnetic field. which of the following would increase the period of the particle's motion? check all that apply. increasing its chargeincreasing its massincreasing the field strengthincreasing its speed

Idon’t know the answer to it and am stuck.