Problem 15: A hot-air balloon rises from ground level, moving straight upward at a constant speed of 6.87 m/s. At 22.6 s after liftoff, a sandbag is accidentally dropped from the balloon. Neglect air resistance. Tran , Theresa 7 ttran55@mail.sfsu,edu @theexpertta.com 7 tracking id: 6C6577E7A0741iB9BD731277. In accordance with Expert TA's Terms of Service. copying this information to any solutions sharing website is strictly forbidden. Doing so may result in termination of your Expert TA Account. Part (a) How long, in seconds, does it take the sandbag to reach the ground from the moment it falls off the balloon? Numeric : A numeric value is expected and not an expression. t = Part (b) How fast is the sandbag moving, in m/s, just before it hits the ground? Numeric : A numeric value is expected and not an expression. 1: =