I need help with the questions n the picture. Please help me thank you :)

2 The displacement of an object from a fixed point O Is given by s(f) = for 05154. Show that the velocity of the object is b Find the velocity and the speed of the object when i = 2. Find the time when the particle changes direction. 3 The displacement a m (from the equi- librium position) of a weight moving In harmonic motion at the end of a spring is modelled byd([) - -sitar- -cooler. where : is measured in seconds, Find the velocity of the objca when I a