If a projectile is shot at an angle of pi/2π2 and at a velocity of 64 m/s64ms, when will it reach its maximum height??

1 Answer
Mar 10, 2018

It reaches its highest point 6.5 s6.5s after launch.

Explanation:

pi/2π2 is straight up so we do not need to calculate a vertical component of the initial velocity. We can use the kinematic formula

v = u + a*tv=u+at

where v = 0v=0 because it stops at maximum height,
u = 64 m/su=64ms,
and a = -9.8 m/s^2a=9.8ms2 which is the acceleration due to gravity, g. The value of a gets a minus sign because it is in the opposite direction of the initial velocity.

v = u + a*tv=u+at

0 = 64 m/s - 9.8 m/s^2*t0=64ms9.8ms2t

Solving for t,

t = (64 cancel(m)/s)/(9.8 cancel(m)/s^2)
(hmmm - I struggled with the formatter here. I wanted to strike out the power of 2 on the s, leaving just s. Would not work for me.)

t = 64 /9.8 s = 6.53 s ~= 6.5 s

I hope this helps,
Steve