What is the speed of a body whose momentum is 9kg * m / s, and its kinetic energy is 4.5J?
| May 31, 2021 | education
p = 9 kg * m / s.
Ek = 4.5 J.
V -?
The momentum of the body p is a vector physical quantity equal to the product of the body’s mass m by its velocity V: p = m * V. The momentum of the body is directed in the same direction as the speed of its movement.
m = p / V.
Kinetic energy Ek is a scalar physical quantity that shows what kind of mechanical work a body can perform. The kinetic energy of the body Ek is determined by the formula: Ek = m * V ^ 2/2.
Ek = p * V ^ 2/2 * V = p * V / 2.
V = 2 * Ek / r.
V = 2 * 4.5 J / 9 kg * m / s = 1 m / s.
Answer: the body is moving at a speed of V = 1 m / s.
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