Question #50b3a

1 Answer
Nov 26, 2017

#V=12+(-10*2)<=>#
#V=12-20m/s<=>#
#V=-8m/s#

Explanation:

If you use the law of speed in the linear uniform movement:
#V=V""_0+a(t-t""_0)#

where
#V # is the final speed
#V""_0 # is the initial speed
#t# is the fianl moment
#t""_0# is the initial moment
and #a# is the acceleration

you will get:
#V=(12+g*2)m/s#
and #g=-10m/s^2# because the ball is thrown straight up
#V=12+(-10*2)<=>#
#V=12-20m/s<=>#
#V=-8m/s#