Terry has fraternal twins, nathan and natalie. even though they are the same age, he knows that nathan will enter a growth spurt about than natalie.

I believe the answer is: two years later

On average, female experience a growth spurt between the age of 10 - 14, while male experience a growth spurt between the age of 12-16.

During this time, they would already experienced the most of their height growth, but their muscle strength would continue to develop until adulthood.

ek = (m·v2) / 2

v - velocity of system after the collision

m = m1 + m2

ek = (m1 + m2) ·v2/2

ek = (200 + 250) ·2,32/2 = 450·5,29/2 = 1190,25 j