A person notices a mild shock if the current along a path through the thumb and index
finger exceeds 81 µA.
A. Find the maximum allowable potential difference without shock across the thumb and index finger for a dry-skin resistance of 5.4 × 105 Ω. Answer in units of V.
B. Find the maximum allowable potential difference without shock across the thumb and index finger for a wet-skin resistance of 2100 Ω. Answer in units of V.

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.