A ball is dropped from the top of a tall building. It took 3.0 secs for the ball to hit the ground. The acceleration of gravity is g = 10 m/sec^2. The initial velocity was 0 m/sec. What was the ball's downward velocity?

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Answer 1 · 2018-02-07T15:45:20

Velocity of ball when it hits the ground is #"30 m/s"#

#v = u + at#

Use above equation of motion.

#v = "0 m/s" + ("10 m/s"^2 × "3.0 s") = "30 m/s"#

Answer 2 · 2018-02-07T15:47:32

#30m/s#

Use one of the kinematic equations:

#v=v_0+at#.

Where #v# is the final velocity, #v_0# the initial velocity, #a# the acceleration and #t# the time.

Here,
#v_0=0m/s#
#a=10m/s^2#
#t=3s#

Input:

#v=0+10*3#

#v=30m/s#