What is a measure of the pulling force of gravity?

Suppose you increase your walking speed from 7 m/s to 13 m/s in a period of 2 s. what is your acceleration?

Coal contains energy. a. light b. kinetic c. chemical d. mechanical

Why does karst topography exist in some geographic location? a. few climates have enough oxygen b. most regions have rock layers other than limestone c. in most regions, the soil is too thin d. the water is too acidic enough in most places