What is the focal length of a lens? A.
the distance between the object and the image
B.
distance between the object and the center of the lens
C.
the distance between the center of the lens and the image
D.
the distance between the focal point and the center of the lens

Iwill give brainliest if you answer right : )

In a good thermo flask the main cause of heat loss is

10 points! will mark brainiest! in a heat engine if 1,000 j of heat enters the system and the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2,000 j 1: write the equation 2: list out your known variables 3: plug the numbers into the equations 4: solve 5: write your solution statement that includes initial energy and final energy added you so much!