Q98
A truck, a car and a motorcycle have equal kinetic energies. If equal, stopping forces are applied and they stop after travelling a distance of X, Y and Z respectively, then
A.
X > Y > Z
B.
X < Y < Z
C.
X - Y = Z
AnswerD.
X ≅ 4Y ≅ 8Z
E.
X = Y = Z
Answer: Option C
Solution
Answer: Option C
Solution:
The work done by the stopping force in bringing a body to rest is equal to its initial kinetic energy.Work done = Force × Distance = Kinetic Energy
If the same retarding force is applied to the truck, car, and motorcycle, and all three have the same kinetic energy, then:
Distance travelled before stopping = KE / Force
Since KE is equal for all and Force is also equal, the stopping distance will be the same for each vehicle.
Therefore:
X = Y = Z
Hence, the correct option is E.