Answer:
The kinetic energy is 20,000\ J
Step-by-step explanation:
The kinetic energy of a body is defined as:

Where <em>m</em> is the mass of the roller coaster car
<em>s</em> is the speed and <em>k</em> is the kinetic energy
We know that 

Then the kinetic energy of the roller coaster car is:

Answer:
4m+5=12
Step-by-step explanation:
4(3)+5#12
right hand side is not equal to left hand side
Answer:
I do not know
Step-by-step explanation:
explain it more
D because both sides have a length of 5