Viên đạn có khӕi lượng m =10g đang bay với vận tӕc v = 100m/s thì gặp một bản gỗ. a) Viên đạn cắm sâu vào gỗ dày d = 4cm. Tính lực cản trung bình của gỗ lên đạn.
b) Tìm vận tӕc viên đạn sau khi ra khӓi bản gỗ chỉ dày d = 2cm

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared

At time t=0, a particle is located at the point (3,6,9). it travels in a straight line to the point (5,2,7), has speed 8 at (3,6,9) and constant acceleration 2i−4j−2k. find an equation for the position vector of the particle.

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?