Answer:
Explanation:
To get the person Moving you have to overcome the static (means not moving) friction coefficient. U(static)
To get the person going at the same speed you have to overcome the kinetic friction coefficient. U(Kinetic)
Force to get him moving is 198 N. Force = ma = U(static)Mg
combining the 2 equations you get 198N = U(static)* 55kg *9.8m/s^2 Solve for U(static)
Same equation to keep him moving except with the dynamic force and the dynamic U
175N= U(kinetic)*55kg*9.8m/s^2 Solve (U dynamic)
Answer:
Work done on an object is equal to
FDcos(angle).
So, naturally, if you lift a book from the floor on top of the table you do work on it since you are applying a force through a distance.
However, I often see the example of carrying a book through a horizontal distance is not work. The reasoning given is this: The force you apply is in the vertical distance, countering gravity and thus not in the direction of motion.
But surely you must be applying a force (and thus work) in the horizontal direction as the book would stop due to air friction if not for your fingers?
Is applying a force through a distance only work if causes an acceleration? That wouldn't make sense in my mind. If you are dragging a sled through snow, you are still doing work on it, since the force is in the direction of motion. This goes even if velocity is constant due to friction.
Explanation:
Answer:
Increase his activity and exercise levels and add more calories to gradually gain weight
Explanation:
My Physics teacher keeps giving us way too much work to do at home.
Answer:
When an electron is hit by a photon of light, it absorbs the quanta of energy the photon was carrying and moves to a higher energy state. One way of thinking about this higher energy state is to imagine that the electron is now moving faster, (it has just been "hit" by a rapidly moving photon)
A photon is a quantum of EM radiation. Its energy is given by E = hf and is related to the frequency f and wavelength λ of the radiation by. E=hf=hcλ(energy of a photon) E = h f = h c λ (energy of a photon) , where E is the energy of a single photon and c is the speed of light.
