Solution of task 295 of Chemistry Book Shimanovich 2003

Solution of task 295 of Chemistry Book Shimanovich 2003

295. If a plate of pure iron is dropped into dilute sulfuric acid, then the evolution of hydrogen on it proceeds slowly and eventually ceases. However, if a zinc stick to touch the iron plate, then on the last begins a rapid release of hydrogen. Why? Which metal dissolves at the same time? Compose the electronic equations of the anodic and cathodic processes