Name: ______Section: ______Date: _____/_____/_____

IP 614

Force Review

Now that we’ve discussed forces for a few days, let’s put together what we know.

  1. What is a force? Write a definition in your own words.
  1. Here is a list of the forces that most commonly appear in physics class assignments. Fill in the table below. Leave yourself some room for corrections or additions.

Note: This list can be useful when drawing force diagrams. If you are not sure which forces are present in a situation, go through this list. For each type of force, ask yourself if that force could be acting in that case. Keep in mind that there can be more than one force of a given type (example: more than one normal force), and that the same object may exert more than one force (example: a floor could exert both a normal force and a friction force).

Type of Force / Symbol / What kinds of things can exert this force? / Direction / When is this force present?
Gravity
Normal
Tension, Spring
Friction
sliding (“kinetic”)
not sliding (“static”)
Drag (air resistance)

There are other types of force as well (buoyant, electric, magnetic…), but they don’t come usually come up at this stage of the course.

  1. Draw a fully labeled FBD of the forces acting on the bicycle. Assume that it is rolling at constant velocity to the left.
  1. Draw a fully labeled FBD of the forces acting on the kid.
  1. Draw and label a free-body diagram for the one piece of paper that fell out of Tommy’s suitcase.
  1. Name one force that does not require contact.
  1. Can the normal force between your feet and the ground ever be more or less than your actual weight? Explain.
  1. Which is the stronger force, the pull of gravity on a scale, or the person’s normal force on top of it?
  1. Describe the motion of an object which has 0 net force acting on it.
  1. Tension—Six blocks hang at rest from various springs. All the springs were 10.0 cm long without any block hanging on them. The length of each spring with its block is shown.
    Rank these situations, from the greatest tension exerted by the spring to the least tension.

Greatest1 ___2 ___3 ___4 ___5 ___6 ___Least

OR the tension is the same (but not zero) for all of these: ______

OR the tension is zero for all of these: ______

Please carefully explain your reasoning.

  1. Graph the following data, calculate the slope after you are done.

Force / Length
0 N / 30cm
1 N / 45cm
2 N / 51cm
3 N / 57cm
4 N / 59cm
5 N / 64cm
6 N / 70cm
  1. Make a graph of this data on the grid to the right. Mark each data point with a dot ().
  1. Draw the best fit line
  1. Choose two points from your line and calculate the slope of the line.
  1. Write the coordinates of each point below (include UNITS!!!):

Point 1: F1 = ______L1 = ______

Point 2: F2 = ______L2 = ______

  1. Calculate the slope of your line. Don’t forget your units*, SHOW YOUR WORK! (Use your calculator; do not leave it as a fraction)