Force And Acceleration Lab

Hi there!
Sorry I forgot to blog yesterday.

Anyway, here's the lab that we did yesterday and today:

First of all we should know the Newton's laws;

First Law - When no net external force is acting on an object, it will either remain at rest or if it is moving, it will continue to move in a straight line at a constant speed.

Second Law - If an unbalanced force acts on an object, the object will undergo an acceleration directly proportional to the magnitude of the force.

Equipment:
Recording Timer
Washers
Lab Cart
Paper clips
Carbon Paper Discs
Pulley
Long Flat board/surface
Timer Tape
String
50 g
100 g
200 g

Procedure:
1. Load the cart with the weights (50, 100 and 200 grams). Attaach one end of the string to the cart. Tie a paper clip to the other end of the string and pass it over the pulley. Hang the metal washers on the clip until the friction force acting on the cart is just offset. Forces due to friction are offset when you can give the cart a very slight push and it moves at a constant speed across the table. Do no removethe added weight at any time.

2. Pull the end of the timer tape through the timer and attach it to and end part of the cart. For the first trial, reemov the 50 g mass from the cart and hang it on the end of the string.

3. Star the timer and release the cart. Stop the timer and the cart when the cart reaches the pulley. Renove the timer tape and label it "50 g trial" on the end that was attached to the cart.

4. Remove the 50 g mass from the string and put it back on the cart. Remove the 100 g mass from the cart and place it on the end of the string. Make and label a second tape in the same way as you made the first tape.

5. Repeat steps 2 and 3 for 150 g, 200 g, and 250 g.(as a result increasing the mass by 50 g each time.) Be sure to place each mass on the cart after using it.

6. In this investigation, wour cart will in general undergo less acceleration than did those of prior investigations. For this reason, it is best to use a larger time interval than thoose used in earlier investigations. Label the first dot on each tape zero. Label every ffith dot after that 1, 2, 3, 4 and so on. The distance between two each numbered dots represents one time interval (a "tock"). The distance between each numbered dot is numerically the same as the avaerage velocity for each time interval. The distance is also numerically the same as the instantaneous velocity for the midpoint of the time interval. Measure each distance on each tape carefully and record al your values.

Interpretation:
1. On the same graph, make a velocity versus time plot for each tape. Plot veloccity on the vertical axis anad the time interval on the horizontal axis.

2. The slope of a velocity time graph is (Vf - Vi)/t, which is the acceleration. Determine the slope of each of the lines on your velocity-time(tock) graph. Record each value.

3. Plot a graph of acceleration versus force with force on the horizontal axis.

4. Explain the meaning of the graph. Does it substantiate Newton's second law?

The next blogger is Thoa:-)