A toy rocket is launched from the ground with velocity v = (5i +12j) m/s.

Find the time taken by the toy rocket to attain maximum height.
Calculate the maximum height attained by the toy rocket.
Calculate the magnitude of the velocity just before it strikes the ground. Neglect the effects of air resistance

1. well, when the rocket achieve the maximum height, it means the velocity in vertical direction is zero.
From the v given, we we know that vertical velocity is 12 m/s. Assume the gravity acceleration is 10m/s/s, so

Vt = Vo - gt
0 = 12 - 10*t
12 = 10t
t=1.2 second


2. The height can be calculated by considering only vertical direction:

h= Vo * t - 1/2*g*t^2
h=(12 * 1.2) - 1/2 * 10* 1.2^2
h= 7.2 m


3. The vertical velocity of rocket is changed by gravity, so when the rocket hit ground the sign is changed to be negative, it means - 12j. Horizontal velocity is constant. so it still 5i
The magnitude is

V= sqrt(5^2 + (-12)^2)
= sqrt(169(
=13 m/s