Đi từ x đến y với vận tốc đi bộ là 5km/h , quay lại thì vận tốc là 6km/h . Tính vận tốc bình quân chung

You are given a vector a = 125i and an unknown vector b that is perpendicular to a. the cross-product of these two vectors is a × b = 98k. what is the y-component of vector b?

Yvette hangs a 2.4kg bird feeder in the middle of a rope tied between two trees. the feeder creates a tension of 480 n in each side of the the rope.

You can watch static electricity in action by rubbing an inflated balloon against your hair. your hair will actually stand on its end! it does this because each hair becomes charged, and they all repel one another.