Can anyone help me slove this question?

  • Thread starter Thread starter dangkykodc
  • Start date Start date
AI Thread Summary
To calculate the terminal speed of a bacterium in water, the drag force equation F drag = −Crv is used, with parameters including a mass of 4 x 10^-15 kg, a drag coefficient of 0.02 N•s/m², and a radius of 1 μm. A force diagram is necessary to determine if the bacterium is in equilibrium, which it is at terminal velocity when the drag force equals the weight. The speed can be calculated using the drag force equation, leading to a specific terminal velocity value. Additionally, the time taken for the bacterium to fall 2.5 m can be derived from this speed. The discussion emphasizes the importance of showing work for effective assistance in solving the problem.
dangkykodc
Messages
1
Reaction score
0
Calculate the terminal speed for a bacterium in water. Use the expression for the drag force in the equation
F drag = −Crv .
Assume the bacterium has a mass m = 4 10−15 kg, a drag coefficient
C = 0.02 N • s/m2 and can be approximated as a sphere of radius r = 1 μm.
a. Draw a force diagram for the bacterium. Is it in equilibrium? Why?
b.Find the speed (size of the velocity) of the bacterium
c.How long does it take a bacterium to fall from the top of a lake of depth 2.5 m to the bottom if it falls at this speed?
 
Physics news on Phys.org
Hi dangkykodc, welcome to PF. The way this homework forum works is that if you show us your work and where you got stuck, we'll be happy to help you. That is why we have the template :)
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Viscosity of liquid for falling sphere viscometer
Replies
6
Views
2K
Drag Force Ratio: Jet vs Transport at 1200 km/h, 15 km Altitude
Replies
6
Views
2K
Linear drag in a liquid and terminal velocity
Replies
1
Views
5K
I Collision when a falling tank impacts the surface of a lake
Replies
7
Views
2K
Sanity check on falling steel ball in water
Replies
5
Views
2K
Need help - Force required for accelerating vehicle
Replies
6
Views
2K
Dropping a penny off a skyscraper.
Replies
14
Views
4K
Drag, terminal velocity, and force.
Replies
9
Views
5K
Can anyone me with this spring question?
Replies
23
Views
9K
What is the drag coefficient of the cue ball
Replies
8
Views
4K

Hot Threads

Recent Insights

Back
Top