A body weighing 1 kg, thrown vertically up from the ground level, fell back. Before hitting the ground, it had a kinetic energy of 200 J. At what speed was the body thrown upward? Neglect air resistance.
To find the speed with which the taken body should have been thrown up, we use the formula (we take into account that without air resistance, the speed of throwing up is equal to the speed of falling): Ek = m * V ^ 2/2, from which we express: V = √ (2 * Ek / m).
Variables: Ek – kinetic energy before impact (Ek = 200 J); m is the mass of the thrown body (m = 1 kg).
Calculation: V = √ (2 * Ek / m) = √ (2 * 200/1) = 20 m / s.
Answer: The taken body should have been thrown at a speed of 20 m / s.
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