275. Горизонтальною поверхнею стола динамометром рівномірно тягнуть брусок, прикладаючи силу 1 H паралельно до поверхні стола. Яка маса бруска, якщо коефіцієнт тертя ковзання 0,25?
Newspapers and magazines play a very important part in our life. Practically there is no family that does not read them. We can learn many things from newspapers. Perhaps that is why many years ago an American humorous writer said: "All I know is what I see in the papers"; and another American author more than half a century ago wrote that "the careful reader of a few good newspapers can learn more in a year than most scientists do in their great libraries".
We can agree or disagree with these statements (better to disagree, because scientific books and magazines have more information than newspapers), but we'll have to say that newspapers help us in many ways. There are a lot of different kinds of newspapers in our country. One can buy them practically everywhere. It is impossible to read all the newspapers and magazines. Everyone has favourite ones.
My favourite newspaper is "Komsomolskaya Pravda". We can read almost about everything in this newspaper. There are articles dealing with home and abroad news, sport events, life of favourite actors and singers and even the weather. We can find many interesting things there. We can read some useful pieces of advice, some stories about our life, and so on. There are puzzles, songs and even anecdotes there. "Komsomolskaya Pravda" is one of the most interesting newspapers, to my mind.
Объяснение:
Newspapers and magazines play a very important part in our life. Practically there is no family that does not read them. We can learn many things from newspapers. Perhaps that is why many years ago an American humorous writer said: "All I know is what I see in the papers"; and another American author more than half a century ago wrote that "the careful reader of a few good newspapers can learn more in a year than most scientists do in their great libraries".
We can agree or disagree with these statements (better to disagree, because scientific books and magazines have more information than newspapers), but we'll have to say that newspapers help us in many ways. There are a lot of different kinds of newspapers in our country. One can buy them practically everywhere. It is impossible to read all the newspapers and magazines. Everyone has favourite ones.
My favourite newspaper is "Komsomolskaya Pravda". We can read almost about everything in this newspaper. There are articles dealing with home and abroad news, sport events, life of favourite actors and singers and even the weather. We can find many interesting things there. We can read some useful pieces of advice, some stories about our life, and so on. There are puzzles, songs and even anecdotes there. "Komsomolskaya Pravda" is one of the most interesting newspapers, to my mind.
1) 240 m
2) 26 м
Объяснение:
1)
Сначала найдем путь в первом случае
S1 = V * 2 - Vo * 2 / 2а
S1 = 900 / 10 = 90м
Теперь во втором случае
Сначала ускорение найдем
а = V - Vo / t
a = 30 / 10 = 3 м/с*2
Теперь найдем расстояние
S2 = V * 2 - Vo * 2 / 2a
S2 = 900 / 6 = 150м
Теперь найдем и общее расстояние
S3 = S1 + S2
S3 = 90 + 150 = 240m
2)
При равноускоренном движении пройденный путь можно определить из уравнения:
s = v * t - (a * t^2)/2
Второй член со знаком минус, потому что автомобиль тормозит;
s = 10 * 4 - 2 * 16/2 = 40м- 16м = 24м;
Автомобиль через 4с будет находится на расстоянии
d = L - s = 50м - 24м = 26м
от светофора.