Suppose an object is moving in a straight line at 50 miles/hr. according to newton's first law of motion, the object will . continue to move in the same way forever, no matter what happens. b. continue to move in the same way until it is acted upon by a force. c. eventually slow down and come to a stop. d. continue to move in a straight line forever if it is in space, but fall to the ground if it is on earth.