sled a (with riders) has twice the mass of sled b (with riders).?

Question

if both sleds have the same kinetic energy which sled is moving faster? explain

Answer 1

sled b because of the equation for energy

KE= 1/2 mass (velocity)^2

Answer 2

Let the mass of sled A = M
let the mass of sled B = m

then M = 2m

KEa = ½ M V²
KEb = ½ m v²

KEa = KEb
½ M V² = ½ m v²
½ (2m) V² = ½ m v²
V² = ½v²

So v > V, or the speed of sled B is greater than the speed of sled A. Further more, it is sqrt(2) times as big!.