Ffrict = Âµ â¢ Fnorm. Return to Top. The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it. There are at least two types of friction force-sliding and static friction. Though it is not always the case, the friction force often opposes the motion of an object.
Answers from Sandhya Pruthi, M.D. No, caffeine doesn't appear to cause breast cysts (fibrocystic breast changes), a noncancerous (benign) breast disease. There's also no evidence to suggest a link between caffeine and breast cancer. Anecdotally, some women report that breast pain symptoms improve when they go off caffeine or reduce the amount of caffeine in their diets. Although no research has documented this effect, it's OK to go to go caffeine-free to see if it relieves discomfort from breast cysts.
Coffee and bladder cancer. The evidence for a relationship between coffee consumption and bladder cancer is inconclusive. Tobacco and exposure to aromatic amines are the two main risk factors for bladder cancer. However, factors linked to lifestyle are also involved.