A block (mass raA) lying on a fixed frictionless inclined plane isconnected to a mass mB by a cord passing over a pulley, asshown in Fig. 4-54. (a) Determine a formula for the accelerationof the system in terms of mA, raB, 0, and g. (b) Whatconditions apply to masses mA and mB for the accelerationto be in one direction (say, mA down the plane), or in theopposite direction? Ignore the mass of thecord and pulley.FIGURE 4-54 67 and 68.
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
