Final answer:
The pressure inside the can has to be sufficiently lower than the external atmospheric pressure to result in a net inward force of 550 N required to crush the can. Without knowing the surface area of the can, an exact numerical value for the pressure cannot be calculated.
Step-by-step explanation:
To determine what the pressure inside the can has to be to crush it by external atmospheric pressure, we need to consider the net force required to crush the can and the difference in pressure between the inside and the outside of the can. Since we are given that the total inward force that will crush the can is 550 N, we need to make sure the external pressure exceeds the internal pressure by an amount that can produce this force. Atmospheric pressure is approximately 101,325 Pascals (Pa), which equates to the force over the surface area the atmosphere is acting upon. If the external pressure remains at atmospheric pressure, the internal pressure will need to be lower to allow for the can to be crushed.
To calculate the required internal pressure to crush the can, we must consider the surface area of the can. However, as the specifics of the surface area aren't provided, we can't perform an exact calculation, so we can only provide a conceptual answer. The internal pressure must be sufficiently lower than atmospheric pressure to result in a net force of 550 N that will crush the can.