Question

A steel sphere of radius 6.5 mm is dropped into a lake. What is the terminal speed of the sphere?

Answer 1

More information. Terminal speed in the water?

Answer 2

Yes, I think we are supposed to assume that it is in water.

Answer 3

The problem here is the assumptions of friction of a small sphere The drag equation is

force drag=densitywater*velocity^2*.47*area

you can calculate area from radius.

at terminal velocity, net force=dragforce

mg-bouyantforce=drag force

now the mass m of the steel ball can be calculated from density steel*volumesphere

bouyant force=densitywater*volumeball*g

do all that, and then you can calculate terminal velocity v of the ball in the water.

Answer 4

Thanks for your help, but I think that it is wrong. I keep getting 1.13 m/s as the answer, so I don't know if I went wrong somewhere.