A projectile is shot from the ground at an angle of #pi/4 # and a speed of #4 m/s#. Factoring in both horizontal and vertical movement, what will the projectile's distance from the starting point be when it reaches its maximum height?

1 Answer
May 20, 2017

The distance is #=0.92m#

Explanation:

Resolving in the vertical direction #uarr^+#

initial velocity is #u_y=vsintheta=4*sin(1/4pi)#

Acceleration is #a=-g#

At the maximum height, #v=0#

We apply the equation of motion

#v=u+at#

to calculate the time to reach the greatest height

#0=4sin(1/4pi)-g*t#

#t=4/g*sin(1/4pi)#

#=0.29s#

The greatest height is

#h=(4sin(pi/4))^2/(2g)=0.41m#

Resolving in the horizontal direction #rarr^+#

To find the horizontal distance, we apply the equation of motion

#s=u_x*t#

#=4cos(1/4pi)*0.29#

#=0.82m#

The distance from the starting point is

#d=sqrt(h^2+s^2)#

#=sqrt(0.41^2+0.82^2)#

#=0.92m#