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Olympics in the disciplines
Assignments for Physics Olympiad
Text Physics Olympiad
1. How to determine the area of a figure cut from cardboard, if there are scales with weights, scissors, paper strip 1 cm wide? 5 points.
2. In a sealed bottle filled with water, there is an air bubble. When the bubble is greater in warm or cold weather? 5 points.
3. Boat going against the current of the river, met the raft. After 35 minutes, following a meeting with a raft boat moored to the bank and stood for 25 minutes. After that, the boat floated down the river in the opposite direction and one hour later overtook the raft at a distance of 5 km from the initial meeting. Determine the rate of flow of the river, believing that speed and boat speed relative to the shore constant. 10 points
4. At the end of the straw sits ant. Straw falls freely, remaining in a vertical position. How to change the duration of the fall, if the ant during fall perepolzet at straws from the bottom up? 7 points.
5. Pans in rapidly boiling water and cook pasta in it. Whether the water is boiling in the tubes of pasta? 7 points.
6. There are two identical steel needles, one of which is magnetized. How do I know which one is magnetized needles without using anything except the spokes?
5 points
7. From the bottom of the reservoir gas bubble pops. Commits any gas work? 5 points
8. Wind carries the ball in a northerly direction. In what direction while rejecting the box attached to the top of the ball? 5 points.
9. On the floor lay a cube and sphere of equal mass, made of steel. Body raised into contact with the ceiling. Are the changed while their potential energy? 10 points.
10.Angliysky Russian merchant says that they have in England density gold 0.697 pounds per inch cube. Russian merchant replied that if the length of a yard measure and weight in poods, the density of gold in Russia =?. What is the density of gold in Russia? (Note: 1 lb = 0.4536 kg 1 inch = 25.4 mm;
1 pood = 16.38 kg; 1 fathom = 3 yards of, or 2.1336 m) 10 points.
Keys to the problems of the Olympiad.
1. Figure M weight proportional to its area (cardboard the same thickness) Use strips of paper as dimensional units should draw a rectangle in the figure with known parties, and cut it to determine the mass m of the rectangle. S area of the whole figure as many times greater than the area of a rectangle s how many times the mass M of the mass m of the rectangle
2. In cool weather fluid is compressed, its volume decreases and the air takes up the entire amount provided.
3. T = 35 min 25 min + + 1:00 = 2:00; S = 5 km; V = S \ t, V = 5:2 = 2.5 km / h
4. Straws fall time decrease
5. No. The water in the cavity pasta boiling, it is necessary to inform the hotter body heat. The water in the saucepan can not be heated above the boiling point.
6. It must be one of the spokes to bring to the middle on the other.
7. Increasing distance from the bottom of the bubble hydrostatic water pressure on it is reduced. Bubble volume increases and the gas does work on filling volume provided by him.
8. He hangs.
9. At the ball less.
The total number of points - 69
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