(20 14? A student in Yimo, Ningbo designed an experiment to explore the relationship between acceleration A and external force F on an object, as shown in figure 1, which is an experimental device dia

(20 14? A student in Yimo, Ningbo designed an experiment to explore the relationship between acceleration A and external force F on an object, as shown in figure 1, which is an experimental device diagram. Solution: (1) As can be seen from the figure, the time interval between two points is T=5×0.02=0. 1s,

According to the fact that the speed at the midpoint of the linear motion with uniform speed change is equal to the average speed in the process, it is obtained that:

v3=x242T=0.237？ 0.1080.2 = 0.65m/s;

According to v3=v 1+at:

a=0.65？ 0.540.2 = 0.55m/S2；

(2) Make an image according to the tracing method, as shown in the figure:

(3) For the a-F diagram, the slope of the image represents the reciprocal of the car mass, while in the a-n diagram, n=Fm0g.

Then a=k 1m0gF+b,

So 1m = km0g.

So the car mass M=m0gk,

When F=0, the acceleration is caused by the sand bucket, so it is: mg=Ma0,

Solution: m=m0gk? bg = m0bk

So the answer is: (1) 0.65; 0.55; (2) As shown in the figure; (3)m0gk； m0bk。