Calculating Force Required to Pull Copper Ball Upward

[shiri]

Calculate the force required to pull a copper ball of radius 3.00 cm upward through a fluid at the constant speed 9.00 cm/s. Take the drag force to be proportional to the speed, with proportionality constant 0.950 kg/s. Ignore the buoyant force.

For this question, do I have to find the mass of a copper ball first, right?

 

[PhanthomJay]

Calculate the force required to pull a copper ball of radius 3.00 cm upward through a fluid at the constant speed 9.00 cm/s. Take the drag force to be proportional to the speed, with proportionality constant 0.950 kg/s. Ignore the buoyant force.

For this question, do I have to find the mass of a copper ball first, right?

You've got an unknown force pulling up, and a drag force acting down. Anything else acting down?

 

[Pyrrhus]

Hello shiri, remember when the speed is constant we have the special case of 1st Law of Newton.

 

[shiri]

Hello shiri, remember when the speed is constant we have the special case of 1st Law of Newton.

if the net force is zero, so is that mean the copper ball is in a constant velocity?