con lắc lò xo dao động điều hòa theo phương thẳng đứng, đầu trên cố định đầu dưới gắn vật m=1kg biết phương trình dao động x=20cos10t(cm), trục tọa độ thẳng đứng chiều dương hướng xuống, gốc tọa độ tại vị trí cân bằng. lực đàn hồi tại vị trí x=10cm

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west