Answer :
Answer:
[tex]s_1 = 21.9 m[/tex]
Explanation:
given,
initial velocity of the first cannon = 22.0 m/s
after 1.5 s second cannon launches at speed = 22 m/s
height where they collide = ?
using equation of motion
[tex]s = u t+ \dfrac{1}{2}at^2[/tex]
[tex]s_1 = u t- \dfrac{1}{2}gt^2[/tex]
[tex]s_2 = u (t - 1.5 )- \dfrac{1}{2}g(t - 1.5)^2[/tex]
for collision s₁ = s₂
[tex]u t- \dfrac{1}{2}gt^2 = u (t - 1.5 )- \dfrac{1}{2}g(t - 1.5)^2[/tex]
[tex]u t- \dfrac{1}{2}gt^2 = ut - 1.5 u - 0.5 g(t^2+ 2.25 - 3t)[/tex]
[tex]-0.5 gt^2 = -1.5 u - 0.5 gt^2+1.5 gt - 1.125 g[/tex]
0 = -1.5 u + 1.5 gt -1.125 g
[tex]t = \dfrac{1.5 \times 22 +1.125 \times 9.8}{1.5 \times 9.8}[/tex]
t = 2.99 s = 3 s
[tex]s_1 = u t- \dfrac{1}{2}gt^2[/tex]
[tex]s_1 = 22 \times 3 - 0.5 \times 9.8 \times 3^2[/tex]
[tex]s_1 = 21.9 m[/tex]