A penny of mass 0.17 kg is placed at the outside edge of a 12'' diameter (or Long Play vinyl) record as shown in the image below. The penny does not slide off but rotates with the record at a constant speed of 0.83 m/s. What is the magnitude of the frictional force acting on the penny, assuming that the coefficient of friction is μ = 0.995? Remember that 1'' = 2.54 cm and give your answer to two decimals.

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

Individuals who live below the poverty line get seriously ill more often than those who do not what could be the hidden variable in this situation?

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".