A constant force is exerted for a short distance on a block of mass that is initially at rest on a horizontal frictionless plane. This force gives the block a certain final speed v. Suppose we repeat the experiment but, instead of starting from rest, the block is already moving with constant speed 2 v in the direction of the force at the moment we begin to apply the force. After we exert the same constant force for the same distance, the increase in the block’s speed 1.( √5+2)v

2. 0

3. v

4. cannot be determined from the informa- tion provided.

5. (√5 − 2) v

6. (√3 − 2) v

7. (√2 − 1) v

8. (√3 − 1) v