Answer;
7.5 seconds
Explanation;
Given u= initial velocity=30m/sec
a= acceleration on moon=1.62m/s2
h=180m
Using the equation
h = u(t) - 1/2gt² {where g = 1.62 m/s²} and u = 30 m/s
180 = 30t - (0.5)(1.62)t²
0 = 0.81t² - 30t +180
solving the quadratic equation for the 2 t-values:
t = 7.5 s or t = 30 s
Therefore; the time taken to reach a height of 180 m upwards is 7.5 seconds
