Answer:
0Joules
Step-by-step explanation:
Kinetic energy is the energy possessed by a body by virtue of its motion. It is expressed mathematically as;
K.E = 1/2mv² where
m is the mass of the object
v is the velocity
Given mass of the cars = 2000kg
Velocity = 50km/hr = 50000m/3600s
Velocity = 13.89m/s
Kinetic energy of the 2000kg identical cars traveling at a speed of 13.89m/s before collision is given as;
K.E = 1/2 × 2000 × 13.89²
K.E = 192,932.1Joules
Their individual kinetic energy before collision is 192,932.1Joules
Their total kinetic energy before collision will be 192,932.1+192,932.1
= 385,864.2Joules
To get the kinetic energy of the bodies after collision, we must first know their common velocity after collision.
According to the conservation law which states that 'the sum of momentum of bodies before collision is equal to the sum of momentum of the bodies after collision.
Momentum = mass × velocity
Before collision, momentum of each bodies will be;
2000 × 13.89
= 27,780kgm/s
After collision their momentum will be;
(2000+2000)v
= 4000v kgm/s²
Using the law to calculate v;
27780+27780 = 4000v
55,560 = 4000v
v = 55,560/4000
v = 13.89m/s
Their KE after collision will then be;
KE = 1/2(4000)×13.89²
KE(after) = 385,864.2Joules
Energy lost due to collision will be KE(before collision) - KE(after collision)
Energy lost due to collision = 385,864.2-385,864.2
Energy lost after collision is 0Joules which shows that no energy was lost after collision.