A train with a mass of 1×106 kg moves with a velocity of 20 m/s. If the velocity is reduced by 10%, what is the percentage decrease in its kinetic energy?
Options
A
1%
B
10%
C
19%
D
21%
Answer & Analysis
Answer
C
Analysis
The kinetic energy of an object is
given by the formula:
Where:
is the mass of the object,
is the velocity of the object.
Initial Kinetic Energy
The initial kinetic energy of the train is:
New Velocity
The velocity is reduced by 10%, so the new
velocity is:
New Kinetic Energy
The new kinetic energy is:
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