Technician A says that silent chains are quieter than roller chains and do not stretch with use. Technician B says that on overhead valve engines, the camshaft is usually placed in the block above the crankshaft. Which technician is correct

A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A nor B

Mutt and jeff are running along a path each pushing a cart loaded with rocks. if mutt's wagon has a mass two times greater than jeff's and they want to stay together, arriving at their destination at the same time, what must happen? a) jeff should slow down so mutt can catch up. b) mutt must use half as much force to push his cart. c) mutt must use twice as much force to push his cart. d) mutt and jeff will use the same force, but mutt will take bigger steps.