A object is thrown straight upwards with a speed of 19.6 m/sec. Three seconds later, its speed is:
Select one:
a. zero.
b. 9.8 m/sec downward.
c. 49 m/sec upward.
d. 29.4 m/sec downward.

Respuesta :

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