Question

a wagon of 20 metric ton moves with 10m/s and collides perfectly inelastic with stationary wagon of 60 metric ton . find loss of kinetic energy

Answer 1

Answer:

                9.75*10^6 Jule

Explanation:From kinetic energy equation and momentum conservation.

                     1 metric ton or 1 ton = 1000Kg

Further explanation attached in the image

                     

Answer 2

Answer:

$7.5\times 10^5 J$

Explanation:

We are given that

Mass of wagon=20 metric ton

1 metric ton=1000 kg

Mass of wagon=20000 kg

Velocity of wagon before collision=10 m/s

Mass of stationary wagon=60 metric ton=60000 kg

We have to find the loss of  kinetic energy when collision is perfectly inelastic.

Kinetic energy before collision=$\frac{1}{2}mv_1^2=\frac{1}{2}\times 20000\times (10)^2=10^6 J$

Linear momentum before collision=Linear momentum after collision

$m_1v_1=(m_1+m_2)v$

$20000\times 10=(20000+60000)v$

$200000=80000v$

$v=\frac{200000}{80000}=\frac{5}{2}=2.5 m/s$

Kinetic energy after collision=$=\frac{1}{2}\times (m_1+m_2)v^2=\frac{1}{2}(20000+60000) (2.5)^2=\frac{1}{2}\times 80000\times (2.5)^2$

Kinetic energy after collision=$250000 =0.25\times 10^6 J$

Loss of K.E=Initial K.E-Final K.E=$10^6-0.25\times 10^6=10^6(1-0.25)=0.75\times 10^6=7.5\times 10^5 J$

Because K.E energy decreases after collision

Hence, the loss in the K.E=$7.5\times 10^5 J$