Consider a very small raindrop slowly falling down in quiet air.Because of the dropâs
small size and low speed, the air resistence to its fall is viscousrather than turbulent.
Consequently, the resistive force is depends linearly on the dropâsvelocity,
~R= -b~v, (1)
where b is a constant which depends on the size and shape of thedrop and the airâs viscosity but does not depend on the dropâsweight of what itâs made of.
Suppose a raindrop of weight mg =0.077 µg à 9.8 m/s2 reachesterminal speed
vt = 0.088 m/s high above the ground. What is the numeric value ofthe coefficient b in eq. (1) for the air resistence to this dropâsmotion?
Answer in units of kg/s.
2)Now consider a plastic pellet of the same size and shape as theraindrop but of a higher density ? p = 3.48Ãdensityofwater. If wedrop it in the middle of the same cloud that produced the raindrop,what would be its terminal velocity vtp?
Answer in units of m/s.
Consider a very small raindrop slowly falling down in quiet air.Because of the dropâs
small size and low speed, the air resistence to its fall is viscousrather than turbulent.
Consequently, the resistive force is depends linearly on the dropâsvelocity,
~R= -b~v, (1)
where b is a constant which depends on the size and shape of thedrop and the airâs viscosity but does not depend on the dropâsweight of what itâs made of.
Suppose a raindrop of weight mg =0.077 µg à 9.8 m/s2 reachesterminal speed
vt = 0.088 m/s high above the ground. What is the numeric value ofthe coefficient b in eq. (1) for the air resistence to this dropâsmotion?
Answer in units of kg/s.
2)Now consider a plastic pellet of the same size and shape as theraindrop but of a higher density ? p = 3.48Ãdensityofwater. If wedrop it in the middle of the same cloud that produced the raindrop,what would be its terminal velocity vtp?
Answer in units of m/s.
