Friction is also a force that, when unbalanced, can change the velocity of an object. What You Will Learn â¢ The magnitude of the force of friction can vary. â¢ Kinetic friction is a force that, when unbalanced, can change the velocity of a moving object. â¢ Static friction balances an applied force and can prevent motion.
It belongs to the group of compounds. known as methylxanthines which include. theobromine (cocoa) and theophylline (tea). Because of its excellent solubility and slow rate. of degradation, caffeine can persist in aquatic. environments (Seiler et al., 2005) and has the. potential to biomagnify through the food chain. Thus, even a small amount of dissolved caffeine. in aquatic environment can concentrate over. time.
For most people, the amount of caffeine in two to four cups of coffee a day is not harmful. However, too much caffeine can cause problems. It can. 1  Make you jittery and shaky. 2  Make it hard to fall asleep or stay asleep. 3  Cause headaches or dizziness. 4  Make your heart beat faster or cause abnormal heart rhythms.