Answer:
Option B, Some of the cars' kinetic energy was converted to sound and heat energy.
Explanation:
In an elastic collision, no energy is lost during and after collision. Thus, it can be said that in an elastic collision both momentum and kinetic energy remains conserved.
While in non-elastic collision, kinetic energy of the system is lost. However, the momentum of the system is conserved. Generally, during and after collision some of the kinetic energy is lost as thermal energy, sound energy etc.
Hence, option B is correct
Answer:
constant at the speed of light
Answer: 735 N
Explanation:
Weight 
is a measure of the gravitational force acting on an object and is directly proportional to the product of the mass 
of the body by the acceleration of gravity 
:
In the case of our planet Earth, the acceleration due gravity is 
. So for a man whose mass is 
, his weight is:
Speed is the rate of change <span>of distance.</span>
