In 2008, the second survey of physics in the third year of high school in the four cities of Suxi Ch

It would be nice to put the doc file on the first floor.

Draw a picture for you, I don't know if it can help you.

As shown in the figure, two parallel smooth metal guide rails are installed on a smooth insulating inclined plane, the guide rail spacing is l, the resistance is negligible and long enough, the inclination angle of the guide rail plane is, and there is a uniform magnetic field of magnetic induction intensity b between the parallel dashed lines Mn and PQ separated by d on the inclined plane, and the direction is perpendicular to the guide rail plane. Another insulating rod with a length of 2d will be a conductor rod and one side long as d (d After release, the device begins to slide along the inclined plane, when the conductor rod moves to the MN place exactly begins to return for the first time, after several round-trips, finally the whole device makes a constant periodic reciprocating motion on the inclined plane. The conductor rod is always perpendicular to the guide rail throughout the movement. Seeking:

2) draw a velocity-time (V-t) image of the entire apparatus during the first sliding; (3) the maximum velocity vm at which the device finally does reciprocating motion on the inclined plane;

(1) Conservation of mechanical energy mgl (1-cos53 degrees) = 1 2mv 2 circular motion f'-mg=mv^2/l

Get f'= (3-2cos53 degrees) mg

Because of the pull of man on the rope f'=f

f=1080n

2) Kinetic energy theorem mg(h-lcos53+d)-(f1+f2)d=0d=mg(h-lcos53) (f1+f2-mg)d=

3) Players start from the lowest point and do a flat toss.

x=vth-l=1/2gt^2

mgl(1-cos53)=1/2mv^2

x=2 x has a maximum value when l=h 2.

L = Therefore, both of them are incorrect, when the length of the rope is closer to the meter, the farther the landing point on the floating platform is from the shore.

Pull force - gravity = centripetal force, pull force = centripetal force + gravity. <2> first calculate the highest point, the kinetic energy theorem, and then use kinetic energy to determine the depth of understanding! <3> I don't know who is right, set the rope length x, use the method of problem 2 to solve it, and throw it flat.

This,I can only do the next problem solving idea.,Although I just graduated this year.,But after all, I forgot.。。。 Combine circular motion with the kinetic energy theorem.

Let the angle of the inclined plane be i, and the friction force of the code is f= mg*cos(i) and oc=l, then the length of the inclined plane is x=l cos(i) overcome the friction force to do work w=f*x= mgl, the larger m, the greater the work.

Acceleration a = g*sin(i) - g*cos(i), the greater the angle, the greater the acceleration a.

v^2=2ax

v = under the root number (2lgtan(i)-2 gl), we can see that there is tan(i) in the v formula, so the larger the angle called i, the greater the velocity v.