Answer:
y2 = 9y1
Explanation:
According to projectile, the formula for calculating maximum height is expressed as;
Maximum height H = u²/2g
If a ball is thrown vertically upward with an initial speed v and reaches a maximum height y1, then
y1 = v²/2g
2g = v²/y1 ..... 1
If the same ball is thrown with an initial speed 3v to reach the maximum height y2, hence;
y2 = (3v)²/2g
2g = 9v²/y2 ..... 2
Equate 1 and 2
v²/y1 = 9v²/y2
1/y1 = 9/y2
Cross multiply
9y1 = y2
Rearrange
y2 = 9y1
Hence the correct relationship between y2 and y1 is y2 = 9y1