A cannon fires a cannonball at an angle of 45° with an initial velocity of 75 m/s off a cliff that is 150 m high?

What is the max height that the cannonball reaches?

What is the total time the cannonball is in the air?

What is the total distance the cannonball travels along the horizontal?

1 Answer

Relevance
  • 2 months ago

    Using v² = u² + 2as we have:

    0 = (75sin45)² - 2gh

    so, h = (75sin45)²/2g => 143.5 metres above point of projection.

    i.e. 293.5 metres above ground

    h(t) = -4.9t² + 75tsin45 + 150

    The cannonball hits the ground when h(t) = -150 so,

    4.9t² - 75tsin45 - 300 = 0

    so, t = 14.9 seconds

    Horizontal distance is 75cos45 x 14.9 => 791.5 metres

    :)>

Still have questions? Get answers by asking now.