The greenhouse effect is a result of A. consumption and radiation of energy in the atmosphere. B. absorption and radiation of energy in the hydrosphere. C. consumption of fruits and vegetables that produce a biofuel.
Balanced forces. When two forces acting on an object are equal in size but act in opposite directions, we say that they are balanced forces. If the forces on an object are balanced (or if there are no forces acting on it), this is what happens: a stationary object stays still a moving object continues to move at the same speed and in the same direction
The downward force of gravity and the upward force of the table supporting the book act in opposite directions and thus balance each other. However, the force of friction acts leftwards, and there is no rightward force to balance it. In this case, an unbalanced force acts upon the book to change its state of motion.