Question

A ping-pong ball is traveling at 10m/s in air, spinning 100 revolutions per second in the clockwise direction. Calculate the lift and the drag force and indicate the direction of the lift (up or down). The ball’s diameter is 3cm and the density of air is 1.2 kg/m 3 .

Answer 1

lift force = 0.213 N

Drag force =
`2*10^-3 N`

Step-by-step explanation:

Given: velocity v = 10 m/s

w = 100 rev/sec

diameter d = 3cm

density D = 1.2kg/m3

lift force =
`16/3*(pi^2*d^3*w*D*v)`

Substituting the values into the equation, we obtain

lift force = 0.213 N

Drag force = C*D*A*v/2

where C = 0.5

substituting the values into the equation again, we have

Drag force =
`2*10^-3 N`