Anonymous
Anonymous asked in Science & MathematicsPhysics · 9 years ago

# a ball rolls off a horizontal roof at 15m/s how far will the ball have fallen vertically when it reaches a spe?

a ball rolls off a horizontal roof at 15m/s

how far will the ball have fallen vertically when it reaches a speed of 24m/s

thanks

Relevance

Speed vertically of 24m/sec will take a height of (v^2/2g) = 29.388 metres to attain.

The v^2 is 24^2, not 15^2, and g used is 9.8.

• If ball rolls of horizontally then it starts to fall with 0 initial vertical velocity.

It takes an object (ball included) 24/g = 24/9.8 = 2.45 s to reach a speed of 24 m/s when Free-Falling from rest (0 vertical speed). The distance of Free-Fall for t = 2.45 s is:

d = 1/2gt² = (0.5)(9.8)(2.45)² = 29 m ANS

• whilst the ball is shifting upwards, this is slowing down. So, this is accelerating downwards. whilst the ball is falling pass into opposite, this is dashing up. So this is accelerating downwards returned. in case you look at a unfastened-physique diagram of the ball (with the exception of wind resistance) the only tension in this is gravity, which factors downward. So, the ball is often accelerating downward.

• 18.7 m

hint: use Pythagoras

Source(s): mes cerveaus