Please help with these i dont know how to do them

The uniform slender bar rests on a smooth horizon- tal surface when a force f is applied normal to the bar at point a. point a is observed to have an initial acceleration aa of 20 m/s2, and the bar has a corre- sponding angular acceleration of 18 rad /s2. deter- mine the distance b.

Amass weighing 24 pounds, attached to the end of a spring, stretches it 4 inches. initially, the mass is released from rest from a point 8 inches below the equilibrium position. find the equation of motion. (use g = 32 ft/s2 for the acceleration due to gravity.)

Abus travels 280km south along a straight path with an average velocity of 88km/h to the south. the bus stops for 24 min, then it travels 210 km south with an average velocity of 75 km/h to the south. how long does the total trip last?