Help me do this science problem

What is the speed of a vehicle that travels 20 meters in 5 second

Which of the activities listed below could limit global warming by slowing the increase in atmospheric carbon dioxide levels? view available hint(s) select all that apply. a. replacing fossil fuels with nuclear energy b. burning vegetation to clear land for agriculture c. limiting soil erosion so organic matter takes longer to decompose d. choosing a fuel-efficient car, or bicycling to school or work e. using more electrical appliances and cars f. cutting down forests to build houses

People keep spending additional units of a particular resource on a want until their marginal benefit is  decreasing withgreater thanless thannot affected by  their marginal cost.