During a snowball fight two balls with masses of 0.4 kg and 0.6 kg, respectively, are thrown in such a manner that they meet head on and combine to form a single mass of 1 kg. the magnitude of intial velocity foreach is 15 m/s. the final kinetic energy of the system just after the collision is what percentage of kinectic energy just before the collision

Considering conservation of momentum;

m1v1 + m2v2 = m3v3

In which,

m1 = mass of snowball 1 = 0.4 kg

v1 = velocity of snowball 1 = 15 m/s

m2 = mass of snowball 2 = 0.6 kg

v2 = velocity of snow ball 2 = 15 m/s

m3 = combined mass = 1 kg

v3 = velocity after comination

Therefore;

0.4*15 + 0.6*15 = 1*v3

v3 = 6+9 = 15 m/s

KE = 1/2mv^2

Then,

KE1 = 1/2*0.4*15^2 = 45 J

KE2 = 1/2*0.6*15^2 = 67.5 J

KE3 = 1/2*1*15^2 = 112.5 J

Therefore, KE3 (kinetic energy after collision) = K1+K2 {kinetic energy before collision). And thus it is 100%.