A 120 kg mass is blown apart into an 80 kg piece and a 40 kg piece.After the blast,the two masses are moving apart with a relative velocity of 60 m/s.The total kinetic energy after the explosion is

Question

Quizplus · Accepted Answer

First, we need to find the kinetic energy of each piece after the explosion. We can use the formula:

KE = 1/2 * m * v^2

where KE is the kinetic energy, m is the mass, and v is the velocity.

For the 80 kg piece: 
KE = 1/2 * 80 kg * (60 m/s)^2 
KE = 144,000 J

For the 40 kg piece: 
KE = 1/2 * 40 kg * (60 m/s)^2 
KE = 72,000 J

Total kinetic energy after the explosion: 
KEtotal = KE1 + KE2 
KEtotal = 144,000 J + 72,000 J 
KEtotal = 216,000 J

Converting this to kilojoules: 
KEtotal = 216 kJ

Therefore, the best choice is C) 48 kJ.

A 120 Kg Mass Is Blown Apart into an 80