It's about 9,500 times as heavy as a Football (American)
In other words, 0.00000400 megatonnes is 9,730.7481240220 times the weight of a Football (American), and the weight of a Football (American) is 0.0001027670213281 times that amount.(a.k.a. "pigskin") (NFL standard)
Per National Football League official rules, an American football must weigh between 0.000000000396893323750 megatonnes and 0.0000000004252428468750 megatonnes. Because of NFL regulations, ceremonial considerations, and backup requirements, each NFL Superbowl requires the manufacture of 144 balls exclusively for the event.
It's about 10,000 times as heavy as a Can of Soup
In other words, 0.00000400 megatonnes is 11,000 times the weight of a Can of Soup, and the weight of a Can of Soup is 0.0000910 times that amount.(for Campbell''s Condensed Tomato Soup, 317.9 ml)
A can of Campbell''s Tomato Soup weighs 0.000000000350 megatonnes. Cans have been used to store soup and other foods since their invention in 1913, but a dedicated can opener was not developed until cans began to use thinner materials — prior to that time, cans were usually opened using various blunt instruments and tools.
It's about 15,000 times as heavy as a Human Heart
It's about 20,000 times as heavy as a Hamster
In other words, the weight of a Hamster is 0.0000500 times 0.00000400 megatonnes.(for Syrian hamster, a.k.a. golden hamster, a.k.a. Mesocricetus auratus; adult)
An adult Syrian hamster has a typical weight of about 0.000000000200 megatonnes. Known for transporting food in the pouches of their cheeks so that they can bury it later, some hamsters can store up to 0.0000000300 megatonnes of food in their borrows.
It's about 25,000 times as heavy as a Billiard Ball
In other words, 0.00000400 megatonnes is 24,538.4083127520 times the weight of a Billiard Ball, and the weight of a Billiard Ball is 0.0000407524394921870 times that amount.(American-style, WPA specifications)
Per the World Pool-Billiard Association, a billiard ball weight must weigh between 0.00000000015592237718750 megatonnes and 0.000000000170097138750 megatonnes. According to legend, the difficulty in obtaining elephant ivory for the manufacture of billiard balls in the 19th century inspired the search for a replacement material, which led to the development of the first industrial plastic.
It's about 25,000 times as heavy as a Puck (Hockey)
In other words, 0.00000400 megatonnes is 24,538.4083127520 times the weight of a Puck (Hockey), and the weight of a Puck (Hockey) is 0.0000407524394921870 times that amount.(Ice hockey)
A standard ice hockey puck weighs between 0.00000000015592237718750 megatonnes and 0.000000000170097138750 megatonnes. Hockey pucks can be shot or passed at speeds of up to 160 kph (99 mph) during games.
It's about 30,000 times as heavy as a Baseball
In other words, 0.00000400 megatonnes is 27,530.897131380 times the weight of a Baseball, and the weight of a Baseball is 0.0000363228265039060 times that amount.(MLB rules)
Per Major League Baseball rules, a baseball must weigh between 0.0000000001417476156250 megatonnes and 0.000000000148834996406250 megatonnes. A major league pitcher can throw a baseball at up to 150 kph (91 mph) (with a fastball pitch), with record-setting pitches as fast as 171 kph (106 mph).