Answer:
The answer is 0.8 m
Explanation:
According the attached diagram, if we take the momentum in the point 0:

Where
mD = mass of Diane = 64.2 kg
mJ = mass of Jack = 93.6 kg
Replacing:


Kinetic energy is formed when the object is in motion.
Potential energy is the energy that is formed relative to others.
One of the example is Corn flour factory.
Corn turned into flour by a windmill that moved by the waterfall. Movement of the mill is relative to the power given by waterfall (potential energy) and the spinning crushes the corn into flour (kinetic energy)
Producers, consumers, and decomposers help to move matter and energy through ecosystems.
Hope this helps! :)
Answer:
17.64 km/h
Explanation:
mass of car, m = 1000 kg
Kinetic energy of car, K = 1.2 x 10^4 J
Let the speed of car is v.
Use the formula for kinetic energy.

By substituting the values

v = 4.9 m/s
Now convert metre per second into km / h
We know that
1 km = 1000 m
1 h = 3600 second
So, 
v = 17.64 km/h
Thus, the reading of speedometer is 17.64 km/h.