4. Identify the reaction force in each case: a. A hammer puts a force on a nail. b. A man pushes a sofa across the floor. c. A magnet attracts a compass needle. d. A girl hauls up on a bucket of water. e. A fan pushes air into the room f. Friction slows down a skidding car. 5. If Bubba (114kg) and his little brother Earl (68kg) are facing each other on ice skates and Earl shoves Bubba who accelerates away at 2 m/s what will be Earl's acceleration