Một vật dđđh với phương trình x = 6cos π t (cm). Thời gian ngắn nhất vật đi từ vị trí x = - 6cm đến vị trí x = 3cm là

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?

12. a body is a particular amount of matter. it can be a solid, liquid or gas. it can be described as existing in a. size and shape. b. motion and force c. time and space. d. location and movement.

What are some important factors to consider when choosing a warm-up before your workout?