Friction is the force that opposes motion.
<h3>What is friction?</h3>
The term friction refers to the force that hinders the movement of a surface over another. The frictional force depends on the nature of the surfaces in contact.
1) The two forces acting on the ball during the frictional force are the forward force and the frictional force.
2) The ball takes more time to roll down the incline in the presence of the cloth because of the increase in friction of the surface.
3) The students repeated the investigation there times in order to ensure accuracy of the results.
4) The energy of the ball changes from potential energy at the top of the ramp to kinetic energy as it rolls down the ramp.
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Answer:
The work done by gravity moving the box up is -514.5 Joules.
Explanation:
The gravity acts in the direction of the displacement, which in this case is negative (ground - top shelf), and so the resulting work is negative. The work is calculated as:

The work done by gravity moving the box up is -514.5 Joules.
Eye strain and self confidence issues.
Answer:
400 W/m^2 and 31℃
Explanation:
The output heat flux q"= 20 W/m^2 (geven)
The output heat flux from.the wall to the air by convection
q"conv = h(ts - t∞)
q"conv = 20(50-30) = 400 W/m^2
Therefor, this case is unsteady and the wall temperature changes with time till the energy balance exist.
ENERGY BALANCE
The input energy must be equal to the output energy for steady state condition. If not the state will be unstaidy or transient.
2. Its noticed that the output heat flux is not that the I put heat flux, therefore the wall tempers will be decreased till the output heat flux is reduced to the value of the given input heat flux
T steady = T∞ +q"/h
= 30 + 20/20 = 31℃
Answer: As with all metals, the alkali metals are malleable, ductile, and are good conductors of heat and electricity. The alkali metals are softer than most other metals.
Alkaline earth metals
The alkaline earth elements are metallic elements found in the second group of the periodic table
Explanation: