Một đoàn tàu bắt đầu rời ga và chuyển đọng thẳng nhanh dần đều. sau ki chạy đc 1,5Km thì đoàn tàu đạt vận tốc 36 Km/h. tính vận tốc của đoàn tàu khi chạy đc 3Km kể từ khi đoàn tàu bắt đầu rời ga

Aball is thrown upward in the air, and its height above the ground after t seconds is h ( t ) = 57 t − 16 t 2 feet. find the time t when the ball will be traveling upward at 14.25 feet per second.

Ann walks 80 meters on a straight line 33 ∘ north of east starting at point 1. draw ann's path. represent ann's walk with a vector of length 80 meters. draw the vector starting at point 1. the length given in the display is in meters.

Imagine that you have two balloons (or, better yet, actually inflate two balloons, if possible). create static electricity around one of the balloons by rubbing it against your hair or your sweater and then bring that balloon close to the other balloon, which has not been charged. try this with at least one other object—and for variety in the discussion, avoid using an object already described by your classmates. then, for your initial post to the discussion, answer the following questions: what happened with the two balloons?