3. Someone at the third-floor window (12.0 m above the ground) hurls a ball downward at an angle of
45 degrees with a speed of 25 m/s. How fast will the ball be traveling when it strikes the sidewalk
below?

Explanation:

Given:

Now we find the vertical component of the initial velocity downwards:

Now the final vertical velocity of the ball when it hits the ground:

using the equation of motion,

Since the horizontal component of the motion is uniform since no force acts in the horizontal direction:

Now the resultant final velocity:

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."