Question #da5cc

1 Answer
Oct 27, 2016

Answer:

#0.2s#, rounded to one decimal place.

Explanation:

Applicable kinematic equations are
#v^2-u^2=2as# .....(1)
#v=u+at# .....(2)
where #s# is distance traveled in time #t#, #u,v and a# are initial velocity, final velocity and acceleration of the object respectively.

Inserting given values in (1), we get (remember initial velocity of the dart is zero.)
#14^2-0^2=2axx1.2#
#=>a=14^2/(2xx1.2)=490/6ms^-2#

Inserting calculated value of acceleration in (2) we get
#14=0+490/6t#
#=>t=14/(490/6)#
#=>t=0.2s#, rounded to one decimal place.