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A object is thrown straight upwards with a speed of 19.6 m/sec. Three seconds later, its speed is:

Select one:

Azero.
B9.8 m/sec downward.
C49 m/sec upward.
D29.4 m/sec downward.

Verified Answer :

Lampa20

We will take that gravitational acceleration is 9.81 m/s^2

Gravitational acceleration will drop objects speed (if object stops it will start going down)

now we calculate how much speed will it drop in 3 seconds
ΔV = 3*9.81 = 29.43

From starting speed we subtract ΔV
V -ΔV = 19.8-29,43 = -9,63

Approximately, this means that V = 9.8m/sec downwards because speed is negative.

Answer is B 

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