1 kilotonne = how many joules, 1 megatonne = ? joules? help

1 kilotonne = how many joules??
1 megatonne = how many joules??

please help, im desperate. :(

1 kilotonne = how many joules??
1 megatonne = how many joules??

please help, im desperate. :(

A megaton (abbreviation MT or Mt) is a unit of energy approximately equivalent to the energy released in the detonation of 1,000,000 tons of TNT

A megaton is defined as 4.2 x 10^15 joule

A kiloton is one-thousandth of a megaton, and so would be equal to 4.2 x 10^12 joule

According to this page, one megaton is 4.6 PJ, even though the page that it links to defines it as 4.2 PJ. This is what happens with an anarchic encyclopedia.
EDIT: I think I've figured this out. The specific combustion energy of TNT is 4.6 MJ/kg, plain and simple. The value 4.2 PJ comes from the measurement of 1 000 000 tons of TNT, whereas the value 4.6 PJ comes from the measurement of 1 000 000 tonnes of TNT.

According to this page, one megaton is 4.6 PJ, even though the page that it links to defines it as 4.2 PJ. This is what happens with an anarchic encyclopedia.
EDIT: I think I've figured this out. The specific combustion energy of TNT is 4.6 MJ/kg, plain and simple. The value 4.2 PJ comes from the measurement of 1 000 000 tons of TNT, whereas the value 4.6 PJ comes from the measurement of 1 000 000 tonnes of TNT.

There are three similar units of mass called the ton or tonne:

tonne (SI) or metric ton = 1000 kg (2204 lb). The official symbol is t, but mT and T are also used.
short ton (or simply ton in casual use in the USA) = 907.185 kg (2000 lb).
long ton (or weight ton) = 1016.047 kg (2240 lb), was commonly used in the UK (before it adopted the 1000 kg tonne) and for petroleum products.

Nice, simple, and confusing, Right?

I'll be more than happy when the US adopts the SI system.