No force is necessary to 1. start an object moving. 2. cause a change in the motion of an ob- ject. 3. stop an object from moving. 4. keep an object moving the way it is al- ready moving. A force is applied to a 1.2 kg mass and pro- duces 4.5 m/s acceleration. What acceleration would be produced by the same force applied to a 5 kg mass? Answer in units of m/s-.