An automobile, the speed of which is increasing at a rate of 0.6ms', travels along a circular road of radius 20m. when the instantaneous speed of the automobile is 4ms-1, find(a)the tangential acceleration components and (b)the magnitude and direction of the total acceleration.

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.