If the horizontal force of 20n is used to pull the object with 60N on the horizontal ground, the object can move at a uniform speed. If the horizontal force of 15N is used to pull the object, the friction force on the object is————

If the horizontal force of 20n is used to pull the object with 60N on the horizontal ground, the object can move at a uniform speed. If the horizontal force of 15N is used to pull the object, the friction force on the object is————

The friction force on the object is 15N
The analysis is as follows
Pull the object with 20n horizontal tension, and the object can move at a uniform speed
It shows that the friction in the process of moving is 20n, that is, the dynamic friction is 20n
The maximum static friction is slightly greater than the dynamic friction
If 15N horizontal tension is used to pull the object, 15N

How small is the friction force when an object moves at a constant speed with a force of 50 N instead of 60 n

Because 50 N is a uniform motion, the friction force is 50 n. when the tension force is changed to 60 n, the friction force is still 50 n
Remember that friction is only related to the weight and coefficient of friction of an object, not to the pulling force
If it helps you, please remember to adopt it_ Thank you