One hot air balloon is 10 meters above the ground and is rising at a rate of 20 meters per minute. A second balloon is 100 meters above the ground and is descending at a rate of 15 meters per minute. In how many minutes will the two balloons be at the same height?

Human factors contributed to climate change through the usage of CFC's common in sprays, aerosols, refrigerant in air conditioners and other manufacturing industries that thins out the ozone layer thereby lessenign the protection from the sun rays. CO2 charged form The non-human factors are volcanic eruptions, solar output and heat generating natural processes. ways to reduce human impact are (1) reduce the use of sprays, aerosols esp. with CFCs; (2) become energy efficient and (3) reducing your wastes.