Both are correct.

perhaps the second 1 is more logical. in both cases its poor john who endures the blow, but the basketball was not set in motion not by itself. ''...... john on his head'' gives a sense of somewhat deliberate action. a ball cant act this way! compare: tom hit terry on his head.(tom has the ability to do it). in such cases its better to use passive forms- john was hit by a ball on his head .