Two cars are moving. The first car has twice the mass of the second car, but only half as much kinetic energy. Then, both cars increase their speed by 8.00 m/s. They then have the same kinetic energy. The original speeds of the two cars are, respectively,

Answer 1

m1 =2•m2,
KE1 =KE2/2.

m1•v1²/2 =m2•v2²/2 = m1•v2²/4.
v1=v2/2.
m1• (v1+8)²/2 = m2• (v2+8)²/2 =
=m1• (v2+8)²/4,
v1 =sqrt(32)= 5.66 m/s.
v2 =11.3 m/s

Answer 2

What if the instead of 8.00m/s it was 6.52m/s?