Edit
In physics, power is the rate of doing work or of transferring heat, i.e. the amount of energy transferred or converted per unit time. Having no direction, it is a scalarquantity. In the International System of Units, the unit of power is the joule per second (J/s), known as the watt in honour of James Watt, the eighteenth-century developer of the condenser steam engine. Another common and traditional measure is horsepower (comparing to the power of a horse). Being the rate of work, the equation for power can be written:
Power
Common symbols
Derivations from
other quantities
P = E/t
P = F·v
P = V·I
P = T·ω
As a physical concept, power requires both a change in the physical system and a specified time in which the change occurs. This is distinct from the concept of work, which is only measured in terms of a net change in the state of the physical system. The same amount of work is done when carrying a load up a flight of stairs whether the person carrying it walks or runs, but more power is needed for running because the work is done in a shorter amount of time.
Answer:
39.2m/s
Explanation:
The potential energy the book has right before it falls is equal to the kinetic energy in falling.
PE = KE
mgh = (1/2)mv
2gh=v
v=(2)(9.81)(2)
v=39.24m/s
Answer:
Fx = 4.92 [N]
Fy = 0.868 [N]
Explanation:
Let's take the 10 degrees as a measure from the horizontal component to the vector.
Thus taking the components in the X & y axes respectively:
Fx = 5*cos(10) = 4.92 [N]
Fy = 5*sin(10) = 0.868 [N]
