Vật khối lượng m = 500g, chuyển động trên mặt phẳng nghiêng (có góc nghiêng   450 so với phương ngang) dưới tác dụng của trọng lực (Hình 2.7). Hệ số ma sát giữa vật và mặt nghiêng là   0,1. Xác định lực ma sát tác dụng lên vật và gia tốc mà vật thu được

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

Ametal ring 4.20 cm in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. these magnets produce an initial uniform field of 1.12 t between them but are gradually pulled apart, causing this field to remain uniform but decrease steadily at 0.240 t/s . (a) what is the magnitude of the electric field induced in the ring? (b) in which direction (clockwise or counterclockwise) does the current flow as viewed by someone on the south pole of the magnet?

Which is a substance that can be separated by physical means and is not the same throughout