The radius of a typical human eardrum is about 4.0 mm. Find the energy per second received by an eardrum when it listens to sound that is (a) at the threshold of hearing and (b) at the threshold of pain.

Lectures 1 2 and 3 Average Speed & Average Velocity vavgdistancetime=dt *speed is a scalar (magnitude with no direction vavgdisplacementtime= rt * velocity is a vector (has direction) → UNITS: ms vavg and r point in direction of motion vx= xf-x0t → xf=x0+t(vx) *with constant velocity Negative slope = negative velocity Steeper slope = faster speed Acceleration aavgvt *rate of change of velocity (slowing, speeding, changing direction) aavgv - n+1 n → UNITS: ms 2 → If v and a are point in the same direction, the object is speeding up afree fall0 ms2 → 1 dimensional acceleration down a slope: as= g(sin) Ki