Kinetic friction Definition and 504 Threads

A horizontal force of 45N is required to accelerate a 5kg block by 4m/s2 on a horizontal surface. I need to find the coefficient of kinetic friction between the block and the surface by assuming g= 10m/s2. How would I go about doing this?

Hey...this problem arose: A force of 40N is required to start a 5 kg box moving across a horizontal concrete floor. A) What is the coefficient of static friction between the box and the floor? (its .82, I got this no problem) B) If the 40N force continues, the box accelerates at 0.7...

5. The drawing shows a large cube (mass = 23 kg) being accelerated across a horizontal frictionless surface by a horizontal force P. A small cube (mass = 3.2 kg) is in contact with the front surface of the large cube and will slide downward unless P is sufficiently large. The coefficient of...

There are 3 blocks on a table. One of the blocks, block C, is in the middle of the table with mass 2M. There are two pulleys on the edges of the tables. The pulley on the left is attached to block C and is attached to block A (which has a mass of M) such that it is hanging off of the pulley and...