ya sure friend,.

 

well u can check out the real proof from any book.....i m jst telling the assumptions made in proof,....

 

1. the temperature of surroundings is considered as constant.

2. due to this the value of temp. of body minus temp. of surrounding can be taken as temp. of surrounding.

 

and hence ultimately we get the equation dT/dt  Temp. of body minus temp. of surroundings....

 

well this law is full of assumptions and it cant be used generally....

 

thanks for sharing the doubt....