Một vật khối lượng 800g dđ đh theo pt v = -12πsin(3πt + π/2) cm/s a) Tính động năng, thế năng, cơ năng tại thời điểm 1s
b) Thế năng, động năng dao động với chu kì bao nhiêu?
c) Tại vị trí nào động năng bằng 3 lần thế năng.

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

(1 point) match the differential equations and their vector valued function solutions. you may wish to multiply at least one solution out fully, to make sure that you know how to do it. you can get the other answers quickly by process of elimination and just multiply out one row element.

Aball is thrown horizontally from a cliff at 8m/s .in what direction is the ball moving 2s later?