The initial speed of a cannon ball is 0.20 km/s. If the ball is to strike a target that is at a horizontal distance of 3.0 km from the cannon, what is the minimum time of flight for the ball

15 seconds

Explanation:

Given that the initial speed of a cannon ball is 0.20 km/s. If the ball is to strike a target that is at a horizontal distance of 3.0 km from the cannon. The minimum time of flight for the ball can be calculated by using the formula for speed

speed = distance / time

Where

speed = 0.2 km/s

distance = 3 km

Substitute the two parameters into the formula

0.2 = 3 / t

make t the subject of the formula

t = 3/0.2

t = 15 s

Therefore, the minimum time of flight for the ball is 15 seconds