Compute the change in mass of the neutron star during the entire process and justify the constant mass assumption made

Aseries circuit consists of a resistor with r = 20 ? , a capacitor with c = 0.01 f, and a decaying battery with e = 300e? 5t. if the initial charge is 0, find the charge as a function of time t

Petroleum contains energy. a. light b. kinetic c. chemical d. mechanical

Am i correct on these two physics questions?