Marek did not succeed with physics that time. Pan Kazimir's words came in one ear and out the other so he understood nothing at all. In front of his eyes there was Katarzhina's smiling face and her laughter kept ringing in his ears. In the end pan Kazimir lost his temper.
"You, young man, do not want to learn at all," he said to Marek, "You are in the clouds! Exactly for dreamers like you were invented rods! Take off your clothes right now and lie down on the box!"
Marek obediently removed his shirt and trousers, pulled down his underpants to his knees, and lay down. The whipping box was made so that the young man's buttocks were higher than his head. When Marek was lying on the box, his ass was unprotected. The young man's buttocks were slightly spread and exposed for blows of the rod. And this only thing made Marek frightened to death.
Pan Kazimir deftly fastened Marek to the box. Two belts under the knees, one belt at the waist and two more belts for the hands. The sun shone through the ivy-covered window of the schoolroom. The teacher took off his jacket and rolled up the sleeves of his shirt. He pulled a long rod from the bucket, passed it through his fist and whipped the air.
"Good rods," said Pan Kazimir, "let's try to remember Newton's second law."
He went to the box, stood behind it and whipped Marek on the buttocks with the rod. Then he whipped the second time and the third. Each time Pan Kazimir struck harder. The pain from the rods was so bright and sharp that the young man could not bear the whipping at all. He began to shout in a voice from the first blows.
"Don't get your head in the clouds in class! Listen to the teacher!"
And painfully whipped the rod on Marek's thin boyish ass. Soon Pani Felicia came running to answer Marek's screaming. The aunt stopped in the doorway and clasping her hands to her chest watched in dismay Pan Kazimir whipping the young man on the buttocks with salt rods. Marek was twisting his body on the box and screeching.
"Oh no, you can't beat him so, Pan Kazimir," said the aunt and went into the classroom.
"For pity's sake, Pani Felicia, it's only a flogging," replied the teacher wiping his sweating forehead with a handkerchief.
They were standing by the box. The aunt looked with the tears in her eyes at Marek's buttocks which were streaked with thin purple stripes.
"Poor boy," Pani Felicia sighed, "you must have pity on him!"
"In this case you should look for another teacher," Pan Kazimir got offended and threw the rod on the floor.
"Ah, do as you consider it necessary!" the aunt waved her hand and quickly left.
Pan Kazimir listened to her footsteps fade away then went to Marek and asked:
"Well, young man, tell me the law of conservation of energy."
In a strange way after a dozen rods Marek's mind suddenly cleared. Katarzhina, with her brown knees sticking out from under her sundress, and her straw-colored hair spilling over her shoulders, had disappeared. The young man abruptly remembered what Pan Kazimir had said to him a quarter of an hour ago.
"The law of conservation of energy says that … the energy of the body never disappears and … does not reappear, it can only transform from one kind to another," said the young man stuttering and sobbing.
"Well-well, it's wonderful," said Pan Kazimir, "I see that your memory has returned. Could you, young man, give some specific examples of this law of the universe?"
Marek could give no examples.
Pan Kazimir took a new rod from the bucket and waved it several times in the air. The whistle of the rod made Marek's buttocks tighten.
"Then, young man," said Pan Kazimir, "follow my thought. The energy of the body never disappears; it can only change from one kind to another."
And then he whipped Marek painfully.
"Here is the kinetic energy," said Pan Kazimir and again he whipped Marek. "Where did that energy go now?"
"I don't know… Don't know, Pan Kazimir," pleaded Marek, "don't hurt me anymore! Please stop!"
"Watch carefully," continued Pan Kazimir, and again he lashed Marek's shivering buttocks with the rod.
The boy screamed.
"What energy has the kinetic energy of the rod transferred to?"
"I don't know, Pan Kazimir.…I can't stand it anymore!"
"The kinetic energy of the rod has been converted into thermal energy," said Pan Kazimir, "and you, young man, can't help feeling it… And now you will feel it again…"
"Oh, it hurts!"
"Do you feel the thermal energy?" Pan Kazimir asked and his voice was a sneer.
"Yes! Yes! I feel it!" Marek shouted. "I understand! I do, I do…"
"Remember, young man, the energy of the body never disappears or reappears, it can only change from one kind to another. Well, let's continue…"
And Pan Kazimir threw the rod into the corner and went to the blackboard.