On earth a ball is thrown straight downward with an initial speed of 1 meter
per second from a height of 15 meters. what is the speed of the ball 0.6
seconds after it is released?
o a) 2.5 m/s
ob) 4.3 m/s
oc) 6.9 m/s
od) 9.0 m/s

-- Gravity adds 9.8 m/s to the downward speed of any object, every second ... as long as there are no other forces messing with it.

-- In 0.6 sec, gravity added (0.6x9.8)= 5.88 m/s to the downward speed of this ball.

-- This ball didn't start from zero. You threw it down with an initial speed of 1 m/s. So after 0.6 sec, with the help of gravity, its speed is

(1) + (5.88) = 6.88 m/s .

Pick choice-C .

Notice that we don't care how high it was off the ground when you threw it, just as long as it was high enough to keep falling for 0.6 sec without hitting the ground.

a.

explanation: