The experiments demonstrate Newton’s first law because the fans act as the unbalanced force. If the fan is blowing in one direction, it will make the cart accelerate, and if there are two fans blowing in opposite directions, the cart will remain at a constant velocity because it is a balanced force. I Activity B: I Place three fans on the cart, all blowing to the left. Question: How do mass and force affect acceleration? 1 . Experiment: Turn on the fans. Click Play and watch the cart, then select the TABLE tab. A. Scroll to the bottom of the table. What is the final velocity of the cart? . 8 m/s B.
How long did it take the cart to reach the end of the track? 4 s 2. Calculate: Acceleration is a measure of how much the velocity of the cart changes each second. To calculate acceleration, divide the final velocity by the amount of time it took to reach that velocity. The units of acceleration are meters per second per second, or m/so. A. What is the acceleration of the cart? (Include units. ) 1. 2 meters per second per second. B. Check your answer on the TABLE tab. Were you correct? Yes. 3. Form hypothesis: a. How do you think changing the mass of the cart will affect its acceleration?
Changing the mass of the cart will affect its acceleration by causing it to accelerate slower than if there was no mass on the cart. A. How do you think the number of fans will affect the cart’s acceleration? The number of fans will affect the cart’s acceleration by causing it to accelerate faster every time a fan is added 4. Experiment: Select the BAR CHART tab and turn on Show numerical values. For each of the situations below, record the acceleration of the cart. 13 fans, O mass units 2 mass units II 13 1. 4 1. 8 11. 2 1. 2 1. 6 Activity B (continued from previous page) 5. Analyze: Look at the acceleration values.
A. How did doubling the force affect the acceleration of the cart? The acceleration to double as well. B. Compare the first and third lines of data. How did tripling the force affect the acceleration of the cart? It tripled the acceleration. C. A cart with two mass units and three fans has twice the mass as a cart with Just three fans. How did doubling the mass affect the acceleration of the cart? It didn’t feet the acceleration of the cart the acceleration stayed the same. 6. Draw conclusions: Newton’s second law states that force is equal to mass times acceleration: F = ma.
This law can be rearranged as a = F / m, or a = m. How does this experiment demonstrate Newton’s second law? This experiment demonstrates Newton’s second law of motion because you can use the data tables to work out the equations. 7. Challenge: The unit of force is the Newton (N). One Newton is the force required to accelerate a I-keg object at a rate of 1 m/so. Suppose each fan supplies a force of 2 N. Use Newton’s second law and the Gizmo to find the following. A. The mass of the cart: B. The mass off fan: C. The mass of one of the draggle mass units:
