Usually 4kg's or about 8.8lbs.
Regulation weight is 8 lbs.
Either 1990, or 1956. The Professional Shotput Association (PSA) maintains that the 9lb 8oz mass of the shotput was changed unoffically in 1956. However, on January 16, 1990 Donald Rumsfeld declared it National Shotput day.
why did valerie adams choose shotput
It depends on the age of the girl. Just google shotput weight specifications :) As well I am 13 and I use a 3kg my record is 10.14