【单选题】2-1 As shown in the figure, an object with mass m tied by a thin thread, which is parallel to an inclined plane, si placed on a smooth inclined plane. If the inclined plane moves toward to left with a...
【简答题】3-2Translation: Newton’s second law implies that: When a body is acted upon by a constant force, its resulting acceleration is inversely proportional to the mass of the body and is directly proportion...
【判断题】When a body oscillating on a horizontal spring passes through its equiibrium position, its acceleration is zero. When the bob of an oscillationg simple pendulum passes through its equilibrium position...
【单选题】Starting at time t = 0, an object moves along a straight line. Its coordinate in meters is given by x ( t ) = 75 t – 1.0 t 3 , where t is in seconds. When it momentarily stops its acceleration is: