A projectile is shot from the ground at a velocity of #7 m/s# at an angle of #pi/4#. How long will it take for the projectile to land?

1 Answer
Oct 11, 2017

#t=(7sqrt2)/20s#

Explanation:

to find the time of flight we use the vertical components

so vertically

#u_y=7sin(pi/4)=(7sqrt2)/2ms^(-1)#

#s_y=0m#

#g=-10ms^(-2)#

vertically

#s_y=u_yt+1/2g t^2#

#=>0=(7sqrt2)/2t-10t^2#

#0=t ((7sqrt2)/2-10t)#

#t=0" "#this is the initial point of the trajectory

#:.(7sqrt2)/2-10t=0#

#t=(7sqrt2)/20s#