Aball is thrown directly upward from a height of 8 ft with an initial velocity of 20 ft/sec. the function s(t) = −16t²+20t+8 gives the height of the ball, in feet, t seconds after it has been thrown. a. determine the time at which the ball reaches its maximum height and find the maximum height. b. how long after the ball is thrown does it land back on the ground?

(a)0.625s (b)1.569s

Explanation:

a.The ball reaches its maximum height when its speed = 0, or changing from positive to negative. To find out the time t for this we need to get the velocity function by taking the first derivative of the height function:

So when v(t) = 0

b. The ball land back on the ground when s(t) = 0:

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..

co2reflects heat radiation back to earth buning coal and oil emits co2 globe warms