Two workers are sliding 400 kg crate across the floor. One worker pushes forward on the crate with a force of 400 N while the other pulls in the same direction with a force of 380 N using a rope connected to the crate. Both forces are horizontal, and the crate slides with a constant speed.
a. What is the crate's coefficient of kinetic friction on the floor?

The crate's coefficient of kinetic friction on the floor is 0.195.

Explanation:

Given that,

Mass of crate, m = 400 kg

Force applied by the first worker,

Force applied by the second worker,

Both forces are horizontal, and the crate slides with a constant speed. It means that the acceleration is equal to 0. As a result, net force is equal to 0. So,

f is frictional force

Here,

is the crate's coefficient of kinetic friction on the floor

So, the crate's coefficient of kinetic friction on the floor is 0.195.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.