6. Nhà Minh cách trường 3km. Lúc 6h15’, Minh đạp xe từ nhà tới trường với vận tốc không đổi. Lúc 6h20’, quãng đường Minh đi được là 0,9km. Hãy tìm vận tốc của Minh và cho biết Minh tới trường lúc mấy giờ?

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

1. explain how you calculate the net force in any direction on the box. 2. suppose an upward force of 15n is added to the box. what will be the net vertical force on the box? 3. what force could be applied to the box to make the net force in the horizontal direction zero? explain. 4. suppose a force of 25n to the right is added to the box. what will be the net force to the right?

Amerry-go-round of radius r, shown in the figure, is rotating at constant angular speed. the friction in its bearings is so small that it can be ignored. a sandbag of mass m is dropped onto the merry-go-round, at a position designated by r. the sandbag does not slip or roll upon contact with the merry-go-round. how would you rank the following different combinations of m and r on the basis of the angular speed of the merry-go-round after the sandbag "sticks" to the merry-go-round from largest to smallest. a) m = 10kg, r = 0.25r b) m = 20kg, r = 0.25r c) m = 10kg, r = 0.50r d) m = 10kg, r = 1.0r e) m = 15kg, r = 0.75r f) m = 40kg, r = 0.25r