Как я провел летние каникулы
Весь список топиков на тему «Мои каникулы / My vacation» смотрите здесь
I think summer is the best season of all because it is warm, the nature is beautiful and we have great opportunities for rest. Summer is a time of holidays. We can go anywhere, spend our time near a river or a lake on fresh, green grass, swim in warm water, or climb mountains, play different games, ride a bicycle and so on.
I spend my summer holidays at my granny’s. There are many things there to do. What I did most of the time - I swam in the sea and sunbathed. Sometimes I made a fire with my friends at the seaside and cooked potatoes there. It was wonderful. We told anecdotes to each other, and did everything we wanted. I also got used to walk alone in the forest.
Как я провел летние каникулы
Весь список топиков на тему «Мои каникулы / My vacation» смотрите здесь
I think summer is the best season of all because it is warm, the nature is beautiful and we have great opportunities for rest. Summer is a time of holidays. We can go anywhere, spend our time near a river or a lake on fresh, green grass, swim in warm water, or climb mountains, play different games, ride a bicycle and so on.
I spend my summer holidays at my granny’s. There are many things there to do. What I did most of the time - I swam in the sea and sunbathed. Sometimes I made a fire with my friends at the seaside and cooked potatoes there. It was wonderful. We told anecdotes to each other, and did everything we wanted. I also got used to walk alone in the forest.
v₀ = 36 км/ч = 10 м/c = 1000 см/c - скорость вагона
ΔS = 3 см - смещение вагона за время пролета пули
S = 2,7 м - ширина вагона
Найти:
v=?
Решение:
v₀ = 10 м/c = 1000 см/c
тогда 3 см вагон пройдет за t = ΔS/v₀ = 3/1000 = 0,003 с
Но это же время пуля летела от одной стенки до другой.
Следовательно,пуля пролетела вагон от стенки до стенки (2,7 м) за 0,003 с.
Тогда скорость пули:
v = S/t = 2,7 / 0,003 = 2700/3 = 900 м/c
ответ: 900 м/с