An object is released from rest at time t = 0 and falls through the air, which exerts a resistive force such that the acceleration a of the object is given by a = g - bv, where v is the object's speed and b is a constant. if limiting cases for large and small values of t are considered, which of the following is a possible expression for the speed of the object as an explicit function of time? v = g(l - e-bt)/b v = (gebt)/b v = gt - bt2 v = (g + a)t/b v = v0 + gt, v0 0 an ideal massless spring is fixed to the wall at one end, as shown above. a block of mass m attached to the other end of the spring oscillates with amplitude a on a frictionless, horizontal surface. the maximum speed of the block is vm. the force constant of the spring is mg/a mgvm/2a /2a /a2 /2a2