Density is mass divided by volume. rho=m/v. So, v=m/rho. In frank's case this is 80/8 = 10 cm^3.
Explanation:
Given that,
Mass of a freight car, 
Speed of a freight car, 
Mass of a scrap metal, 
(a) Let us assume that the final velocity of the loaded freight car is V. The momentum of the system will remain conserved as follows :

So, the final velocity of the loaded freight car is 0.182 m/s.
(b) Lost on kinetic energy = final kinetic energy - initial kinetic energy
![\Delta K=\dfrac{1}{2}[(m_1+m_2)V^2-m_1u_1^2)]\\\\=\dfrac{1}{2}\times [(30,000+110,000 )0.182^2-30000(0.85)^2]\\\\=-8518.82\ J](https://tex.z-dn.net/?f=%5CDelta%20K%3D%5Cdfrac%7B1%7D%7B2%7D%5B%28m_1%2Bm_2%29V%5E2-m_1u_1%5E2%29%5D%5C%5C%5C%5C%3D%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%20%5B%2830%2C000%2B110%2C000%20%290.182%5E2-30000%280.85%29%5E2%5D%5C%5C%5C%5C%3D-8518.82%5C%20J)
Lost in kinetic energy is 8518.82. Negative sign shows loss.
How can I help? What’s the question?
Answer:
<em>When a moving car brakes to a stop the </em><em>kinetic energy of the car is converted to heat energy.
</em>
Explanation:
A moving car has kinetic energy.
It is given by the equation 
Where m denotes mass of the car and v denote sits velocity. When the brakes are applied the velocity becomes zero and the car doesn’t possess kinetic energy anymore.
According to law of conservation of energy can neither be created nor be destroyed but can only be transformed from one form to another. On coming to a stop, the kinetic energy of the car gets converted to heat. The friction between the tyre and the road heats up the tyre.
<span>Reduce energy use.
Change the way you think about transportation. Walk or bike whenever possible.
Insulate your home. Insulate yourself and your home.
Make every drop count.
</span>Cool wash and hang to dry.
<span>Switch to "green power.
</span>Recycle.