In an arcade game a 0.076 kg disk is shot across a frictionless horizontal surface by com-
pressing it against a spring and releasing it.
If the spring has a spring constant of
219 N/m and is compressed from its equilibrium position by 4 cm, find the speed with
which the disk slides across the surface.
Answer in units of m/s.

When a lead acid car battery is recharged by the alternator, it acts essentially as an electrolytic cell in which solid lead(ii) sulfate is reduced to lead at the cathode and oxidized to solid lead(ii) oxide at the anode. suppose a current of is fed into a car battery for seconds. calculate the mass of lead deposited on the cathode of the battery.