<h2>a) Average velocity in first 4 seconds is 64 ft/s upward</h2><h2>b) Average velocity in second 4 seconds is 63.5 ft/s downward</h2>
Explanation:
a) Given S(t) = 76 + 128t − 16t²
s(0) = 76 + 128 x 0 − 16 x 0² = 76 ft
s(4) = 76 + 128 x 4 − 16 x 4² = 332 ft
Displacement in 4 seconds = 332 - 76 = 256 ft
Time = 4 - 0 = 4 s

Average velocity in first 4 seconds is 64 ft/s upward
a) Given S(t) = 76 + 128t − 16t²
s(4) = 76 + 128 x 4 − 16 x 4² = 332 ft
s(8) = 76 + 128 x 8 − 16 x 8² = 78 ft
Displacement in 4 seconds = 78 - 332 = -254 ft
Time = 4 - 0 = 4 s

Average velocity in second 4 seconds is 63.5 ft/s downward
Hmmm...maybe it would be because since you're staying still then things appear to go by quickly.
The magnitude of the downward acceleration of the hollow cylinder is 6m/s^2.
Z = I α
T.R =1/2 M (
+
)α
T.R = 1/2M 5
/4 α
T = 5Ma/8
Mg - T = Ma
Mg - 5Ma/8 = Ma
Mg= 5Ma/8 + Ma = 13Ma / 8
acceleration = 8g/13 = 6 m/s^2
The rate at which an object's velocity with respect to time changes is called its acceleration. The direction of the net force imposed on an item determines its acceleration in relation to that force. According to Newton's Second Law, the magnitude of an object's acceleration is the result of two factors working together
The size of the net balance of all external forces acting on that item is directly proportional to the magnitude of this net resultant force; the magnitude of that object's mass, depending on the materials from which it is built, is inversely related to its mass.
Learn more about acceleration here:
brainly.com/question/2303856
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a) El Niño is defined as an abnormal weather pattern caused by the warming of the Pacific Ocean near the equator, off the coast of South America. The sun warms the water near the equator, which can make more clouds and, therefore, more rain. It has detrimental effects on biodiversity leading to its large-scale loss by
warmer sea temperatures leading to plankton and fish kills in coastal waters
lower sea levels leading to exposure of underwater coral reefs, causing their loss.