A box of mass 10kg is pulled up by a string. If the acceleration of the box is 20m/s^2, what is the tension in the string?

Plss anybody know how to do this? ? i need the answers from a through d

The dot diagram represents the motion of the motorcycle as it moves from left to right

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.