# Calculate change of pressure in a football due to insertion of a solid ball [closed]

Let's say I have a football of radius r1 inflated to pressure p1 and insert a solid metal ball of radius r2 (without losing any air), to give a new pressure of p2.

Is there a formula I can use that gives me p2 in terms of r1, r2 and p1?

## closed as off-topic by Aaron Stevens, ZeroTheHero, Buzz, Kyle Kanos, Jon CusterJan 7 at 14:35

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If this is carried out without any change in temperature(isothermally)(which is a very good approximation), you can use

$$P_1V_1=P_2V_2$$

Use $$V_1$$ as initial volume of balloon(spherical) and $$V_2$$ as the final volume of air remaining.