A 2.0 kg mass moving at 5.0 m/s suddenly collides head-on with a 3.0 kg mass at rest. If the collision is perfectly inelastic, how much kinetic energy was lost during the collision? (a) 20 J
(b) 26 J
(c) 15 J
(d) 8 J

correct answer is (c) 15 J

Explanation:

given data

mass m1 = 2 kg

velocity V1 = 5 m/s

mass other  = 3 kg

so mass m2 = 2+ 3 kg = 5 kg

solution

we will apply here conservation of momentum:

m1V1 = m2V2  1

put here value and we get  velocity v2

(2.0) × (5.0) = (2.0 + 3.0) × V

solve it we get

10 = 5 × V 2

V2 = 2.0 m/s

so here kinetic energy will be

KE = ½ × m × v²

so

∆KE = ½ × m1 × (v1)²  -  ½  × m2 × (v2) ²

∆KE = 0.5 × 2 × 25 - 0.5 × 5 × 4

 ∆KE = 25 - 10

∆KE  = 15 J

they are non-matter

explanation:

they are non-matter. basically, any type of energy or any abstract concept is an example of something that does not matter. other examples include dreams, magnetism, radio, and hate

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min