Force and Motion Essay
Activity 1-1: Introduction to Force
1. Place one end of a rubber band around the vertical rod on your table.
2. Stretch the rubber band to a length of 10cm beyond its unstretched length, L0.
3. Place two rubber bands around the rod and stretch them together a length of 10cm
Question 1-1: How does the combined force of two rubber bands compare to the force of just one rubber band?
1. Repeat with 3, 4 5 rubber bands.
Activity 1-2: Measuring Force with a Force Probe
Open file L03A1-2a (Measuring Force.ds)
Note: The Force Probe is attached to a cart.
1. Zero the Force Probe. (With nothing attached to the Probe press "Start" on the control panel and observe the force. If it …show more content…
Record the force in Newtons. _______N
13. Repeat Steps 12-14 with 3 and 4 rubber bands.
14. Record all measurements in Data Table 2.
Question 1-2: Use Data Table 1. a) Is the ratio of force (F) to length (L) approximately constant? _______
b) Is the force (F) directly proportional to the distance the rubber band is stretched (L)? ________
c) Is the force exerted by the rubber band in the same or opposite direction as the direction the rubber band is stretched? _____________
The force exerted by a stretched rubber band or spring can be expressed as shown below?
F = -kL…equation 1-1 (elastic force law or Hooke’s Law)
L = the distance stretched beyond its equilibrium length
K= elastic force constant
d) What are the SI units of the elastic force constant, k? _______
Question 1-3: Use Data Table 2. e) Is the force with four rubber bands twice the force with two rubber bands? _________
f) Is the force directly proportional to the number of rubber bands? ________
Close file L03A1-2a (Measuring Force.ds)
Activity 2-1: Pushing and pulling a cart
Open file L03A2-1(Motion and Force.ds)
1. Place the cart with Force Probe attached on the track as shown below.
2. Zero the Force Probe.
3. Grasp the Force Probe hook.
4. Click "Start"