On the horizontal table, pull a 200N wooden block to the right along the horizontal direction with a spring dynamometer at a constant speed, and the indication of the spring dynamometer is 50N 【1】 Try to analyze the force on the block, and the force diagram, and find out the size of the force 【2】 If the indication of the spring dynamometer increases to 60N, what is the friction force on the block? What is the resultant force on the block? What is the motion state of the block?

On the horizontal table, pull a 200N wooden block to the right along the horizontal direction with a spring dynamometer at a constant speed, and the indication of the spring dynamometer is 50N 【1】 Try to analyze the force on the block, and the force diagram, and find out the size of the force 【2】 If the indication of the spring dynamometer increases to 60N, what is the friction force on the block? What is the resultant force on the block? What is the motion state of the block?

1. The wood block is subjected to four forces: downward, upward, left and right: the vertical gravity and the ground supporting force, the size of which is 200N; the horizontal sliding friction to the left and the horizontal pulling force to the right, the size of which is 50N
Sketch Description: a square represents the object under force, and four arrows from the center of the square indicate four forces. The length of the arrow is drawn according to the force (sketch)
2. The friction force is still 50 N (because the two factors that affect the sliding friction force, i.e. the pressure and the roughness of the contact surface, do not change, and the increase of the tensile force does not affect the friction force at this time)
The resultant force on the block is 10N. (F = f pull-f friction)
The block will accelerate to the right