Three identical balls are thrown from the same height off a tall building. They are all thrown with the same speed, but in different directions. Ball A is thrown in the horizontally, parallel to the roof; ball B is thrown at an angle 45° above the horizontal; ball C is thrown at an angle 45° below the horizontal. Which ball has the greatest speed just before it hits the ground? Assume that the ground near the building is level, and ignore any effects due to air resistance.

three balls have the same speed

Explanation:

In a parabolic motion we have that

but the time just before the balls hit the ground is

Hence we have

ball A

ball B

ball C

Hence, all three balls have the same speed just before hit the groug

vA=vB=vC

I hope this is useful for you

regards

"i have always loved contemporary art and made it a general goal to work within the field. after a few nonprofit internships at museums and galleries, i decided to try the for-profit art world and was offered a job as the ad assistant at the magazine. i much prefer the pace of the for-profit art community and have stayed with the company for three years, with a promotion to an account manager last spring."

i just did this and got a 100.

the answer is 12 as i may remember

: )