Two airplanes simulating a dogfight are headed right for each other, plane A moving at \(285 \mathrm{~km} / \mathrm{h}\) and plane B moving at \(295 \mathrm{~km} / \mathrm{h}\). The electronic machine gun on A can emit 300 rounds per minute, with each round accompanied by a sound pulse.

(a) How many pulses does the pilot in B hear during a burst that lasts \(10 \mathrm{~s}\) according to observer \(A\) ?

(b) How long does the burst last for the pilot in B?