an object is shot vertically upward into the air with an initial velocity of 20 m/s? which of the following correctly describes the velocity and acceleration of the object after 4seconds?
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Answer:
Answer is (C)
Explanation:
For acceleration
• If the motion is vertically, then acceleration is 9.8 m/s²
» Upward motion, acceleration is negative (-9.8)
» Downward motion, acceleration is positive (+9.8)
For velocity
[tex]{ \rm{v = u + gt}} \\ { \rm{v = 20 + ( - 9.8 \times 4)}} \\ { \rm{v = - 19.2 \: m {s}^{ - 1} }}[/tex]