A .Measure a pencil, end to end. Draw a sketch of the pencil and show your measurements. If you were to balance the pencil horizontally on your finger, where do you think it would be balanced? Note this on your sketch, and write down your hypothesis (distance from each end) and your prediction. b. Now test your hypothesis. Balance the pencil on your finger horizontally. When it is balanced, your finger is at the center of gravity. Note and make a mark where your finger is in relation to each end of the pencil.
c. Measure from one end of the pencil to where your finger balanced it. Show this on your sketch, and record the data it in your chart.
d. Repeat steps b-c a second time for the pencil.
e. Repeat steps a - d using a pen and crayon as well.
f. What are your results? Compare your results with your hypothesis and then write an explanation in a conclusion. Which item has a center of gravity closer to the actual center that you measure?

First off you have to do this and show a presentation , so i can't really help , sorry :/

Explanation:

in the middle close to and end

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.