The kinetic energy of the body is 10 J. What work must be done to increase its speed 2 times.
| February 19, 2021 | education
Initial kinetic energy of the body (10 J): Ek1 = m * V1² / 2, where m is the mass of the body, V1 is the initial velocity of the body.
Kinetic energy of the body after increasing the speed by 2 times: Ek2 = m * V2² / 2, where V2 = 2V1.
Ek2 = m * V2² / 2 = m * (2V1) ² / 2 = 4 * m * V1² / 2 = 4Ek1 = 4 * 10 = 40 J.
The work to increase the speed of the body by a factor of two will be equal to the difference in the kinetic energies of the body: A = Ek2 – Ek1 = 40 – 10 = 30 J.
Answer: To increase the speed of the body by 2 times, it is necessary to perform work of 30 J.
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