After the first stage separates the second stage ignites and the astronauts are jolted back Apollo 13?

In the Apollo 13 mission, after the first stage of the Saturn V rocket completed its burn and separated, the second stage ignited to continue propelling the spacecraft toward orbit. The astronauts experienced a significant jolt as the powerful engines of the second stage ignited, which was a normal part of the launch sequence. This sudden acceleration was felt as a force pushing them back into their seats, marking a critical moment in their journey to the Moon. Despite the subsequent challenges they faced, this stage was crucial for achieving the necessary velocity for the mission.