How much work is done by an applied force to lift a 45 newton block 6.0 meters at a constant speed ?

Awheel rotates without friction about a stationary horizontal axis at the center of the wheel. a constant tangential force equal to 82.0 n is applied to the rim of the wheel. the wheel has radius 0.150 m . starting from rest, the wheel has an angular speed of 12.8 rev/s after 3.88 s. what is the moment of inertia of the wheel?

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

What is friction? how does it affect the motion of an object?