Pondering the Giant Nerf

Somehow a 25 kg Nerf ball came up in a conversation with Thomas (such things are not uncommon). And in a fit of mathematics (my second in as many weeks). I figured out what it would be like.

First up: "How big would it be?" This is easy, measure the size and weight of a standard Nerf ball (45 mm diameter and 5 g mass) then the quick use of some cube ratio math to get the big boy's size. This came out to a huge 760 mm diameter sphere.

Second up: "What if it fell on your head?" This required a some wiki-based research to get a few equations and some searching for coefficient of drag of a sphere with a rough surface. After a few calculator button pushings the answer came out: 5 m/s or 18 km/h or 11 mph. The real world equivalent would be a small child running in to you really fast. This would hurt you, but probably not kill you. Probably.