Online Assignment 2
Please visit this URL: http://www.flickr.com/photos/physicsclassroom/galleries/72157625278916478/
Take a look at the pictures.
For the tug of war, draw a freebody diagram for one person involved in the tug of war.
Explain why the tug of war demonstrates Newton’s 2nd and 3rd laws.
For the hammer hitting the glass explain why the stationary glass has been set into motion by the hammer.
Explain why the screw is not falling over.
Explain why the boy with the hovercraft uses the blower to pump air into the bottom of his hovercraft.
Explain why we play ice hockey instead of “dirt hockey” or “floor covered with sandpaper hockey”
Draw a freebody diagram for the water spider. You may want to draw it from a different angle. Calculate the surface tension needed to keep a .1kg spider from sinking.
Explain why the picture of the diver shows a greater distance between him at each step as he falls.
Please visit this URL: http://phet.colorado.edu/en/simulation/forces-and-motion
Run the simulation and find how much force it takes to start the box moving and how much it takes to keep it moving. Compare this to what you would calculate. (Any discrepancy is due to the difficulties with the simulation.)
Please visit this URL: http://phet.colorado.edu/en/simulation/lunar-lander
You can play the game but then answer these questions:
1. What force is the rocket providing to the spaceship?
2. Why does the spaceship need this force to avoid being destroyed?
3. How does the magnitude of the force in problem 1 change as the fuel in the spaceship is consumed?
Turn the vectors on and play again. Try and create these situations:
A. The spaceship is suspended motionless
B. The spaceship has positive velocity and acceleration
C. The spaceship has negative velocity and acceleration
D. The spaceship has positive velocity and negative acceleration
E. The spaceship has negative velocity and positive acceleration.
Answer these questions:
1. Draw freebody diagrams showing situations A-E above.
2. Label the diagrams with acceleration and velocity vectors as well as force vectors. A should not have acceleration or velocity vectors.