Time vs Speed

Guiding Question: What affects the speed of an object?

Hypothesis: We think that weight and mass affect speed because the heavier the object is the more gravity pulls on it and then it goes faster.

Manipulated variable: speed of the balls, distance of the ball from a reference point

Controlled variable: weight, mass and density of the ball

Responding variable: The speed of the balls to change according to the weight and mass of the ball.

Materials

1.       3 different sized balls

2.       Rubber band

3.       Stop watch

4.       One wooden track

Procedure

1.     Collect materials that are written above

2.     Lay the track flat on the floor

3.     Measure 1 and a half meters when it is laying flat

4.     Test each ball three times on the track (time how long it takes the ball to travel from point a to b.)

5.     Do that three times.

6.     Then find the speed for every object by dividing distance by time.

7.     Find the average of the speed and time of each ball

8.     See if the hypothesis was correct or wrong 

Key Terms:

What is a force?

A force is a push or pull upon an object resulting from the object's interaction with another object. Whenever there is an interaction between two objects, there is a force upon each of the objects. When the interaction ceases, the two objects no longer experience the force. Forces only exist as a result of an interaction.

What is Friction?

Friction is a force that resists sliding motion between surfaces that are touching. 

What is momentum?

Momentum refers to moving things. It is a product of the mass of an object and its velocity. Momentum is why the driver of a car applies the brake to stop the car rather than just taking his foot off the accelerator. The car has gathered momentum and will continue to move forward after the driver stops accelerating it.

How do these 3 affect speed of an object?

Momentum affects speed because momentum is the object’s mass times the objects speed.

Friction affects speed because it slows down the object. For example, when you are riding a bike downhill, first you are going fast but as you stop going downhill you will slow down, that is because of friction.

      Force affects speed because without force, the object can’t move. And the more force you put into the object, it      will  go faster.

Table and Graph:

 

Data analysis:

On my graphs I can see that the average time and speed was lowest for the tennis ball. I think that this is very weird because i would expect the biggest and heaviest ball shout be the slowest. I also see that the 3 trials for the Styrofoam ball were the most alike. I think that in some balls we put too much force, and in some too little. So I don't think our data is that accurate.

Conclusion: 

My hypothesis was correct because all the things I listed do affect speed, but there are more things than that that affect the speed of an object. 

Momentum affects speed because momentum is the object’s mass times the objects speed.

Friction affects speed by slowing the ball down. For example, when you are riding a bike, it will eventually slow down and stops because of friction.

Force affects speed because the stronger the force the faster the object in motion, and the weaker the force the object will go slower.

From this lab I learned that it doesn’t matter if the ball is larger than the other ball, it all depends all on the force, density and many more things. In this case the Styrofoam ball went the smoothest.

Further Inquiry:

             During our Test we made only one mistake. On some balls we put too much force, and on some too little. That causes our data not to be that accurate. Next time if I do something similar, I will probably use a ruler, or rubber band.