Adriver speeds along a curved road and sees a fallen tree on the road. he applies the brakes but is unable to stop in time. when the car hits the tree, it slows down from 6 meters/second to 0 meters/second. what was the change in velocity during this time? the change in velocity during the collision was   meters/second. need it fast

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.