Trường hợp nào dưới dây có thể coi là chất điểm A. trái đất trong CĐ tự quay quanh mình nó với nhau
B. hai hòn bi lúc va chạm
C. người nhảy cầu lúc đang rơi xuống nước
D. giọt nước mưa lúc đang rơi

Aprojectile is launched from ground level with an initial velocity of v 0 feet per second. neglecting air resistance, its height in feet t seconds after launch is given by s equals negative 16 t squared plus v 0 t. find the time(s) that the projectile will (a) reach a height of 192 ft and (b) return to the ground when v 0equals112 feet per second. (a) find the time(s) that the projectile will reach a height of 192 ft when v 0equals112 feet per second. select the correct choice below and, if necessary, fill in the answer box to complete your choice.

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

Ways that industry and agriculture use physical properties to separate substances