Three balls of the same size, marble, copper and iron, move at the same speed. which ball has

| June 14, 2021 | education

Three balls of the same size, marble, copper and iron, move at the same speed. which ball has the minimum kinetic energy?

ρmr = 2700 kg / m ^ 3.
ρmed = 8900 kg / m ^ 3.
ρzhel = 7800 kg / m ^ 3.
The kinetic energy of the body Ek is determined by the formula: Ek = m * v ^ 2/2, where m is the mass of the body, v is the speed of its movement.
The mass of the body m is expressed by the formula: m = ρ * V, where ρ is the density of the substance from which the body is made, V is the volume of the body.
The kinetic energy of the body Ek will have the form: Ek = ρ * V * v ^ 2/2.
Since we have balls of the same size and have the same speed, then Vmr = Vmed = Vdir and vmr = vmed = vwish, then the kinetic energy will be lower for the body with the lowest density.
Answer: the kinetic energy will be the smallest for a marble ball, average for an iron ball, the highest kinetic energy for a copper ball.



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