Question #fdb55

1 Answer
Jul 16, 2016

(a)8.34s and (b )699.81m

Explanation:

Horizontal component of the velocity of decoy is
#=303.9xxcos30"km"/"hr"#

Horizontal displacement of decoy from release point is

#=610m=0.61km#

So the time of flight

#T="Horizontal displacement"/"Horizontal component of velocity"#

#=(0.61km)/(303.9xxcos30 "km"/"hr")xx(3600s)/"hr"=8.34s#

Initial vertical component (downward) of the velocity of decoy is
#=303.9xxsin30"km"/"hr"xx(1000m/"km")/(3600s/"hr")=42.21m/s#

Taking acceleration due to gravity #g =10m/s^2#

The net vertical displacement during time of flight which is the

height of the release point is given by

#H=uxxT+1/2xxgxxT^2#
#=42.21xx8.34+1/2xx10xx(8.34)^2=699.81m#